PSPM 1 PSPM 1 CHOW CHOON WOOI
2012 - 2020 (Q&A)
MATRICULATION
MATHEMATICS
KEDAH
MATRICULATION
COLLEGE
1
TABLE OF CONTENTS Page CHOW CHOON WOOI
3
Year
2012/2013 49
2013/2014 92
2014/2015 137
2015/2016 194
2016/2017 247
2017/2018 289
2018/2019 330
2019/2020 368
2020/2021
2
2012/2013
3
CHOW CHOON WOOI
QS 015/1 CHOW CHOON WOOI
Matriculation Programme
Examination
Semester 1
Session 2012/2013
4
PSPM 1 QS 015/1 Session
2012/2013
1. Find the value of x which satisfies the equation
2(5 − ) − 2( − 2) = 3 − 2(1 + )
2. Determine the solution set of the inequality
11 CHOW CHOON WOOI
2 − 1 < + 2
3. Given + 2, − 4, − 7 are the first three terms of a geometric series. Determine the
value of . Hence, find the sum to infinity of the series.
4. Given a complex number = 1 − √3 . Determine the value of if ̅ ̅ ̅2 = 1 .
̅
5. (a) Matrix M is given as [−34 −41]. Show that 2 = 7 − 8 , where I is the 2 x 2
identity matrix. Deduce that −1 = 7 − 1 .
88
+ 1 −1 1
(b) Given matrix = [ 3 2 4 ] and | | = 27. Find the value of , where
−1 0 + 2
is an integer.
6. The functions and are defined as ( ) = 3 +4, ≠ 2 and ( ) = 3 − .
−2
(a) Find −1( ) and −1( ).
(b) Evaluate ( ⃘ −1)(3).
(c) If ( ⃘ −1)( ) = 2, find the value of .
3
7. (a) Solve | 2 − − 3| = 3.
(b) Find the solution set of the inequality 2 2+9 −4 < 4.
+2
8. The first four terms of a binomial expansion (1 + ) is
1 + − 1 2 + 3 + ⋯
2
Find
(a) the values of a and n where ≠ 0.
Page 2
5
PSPM 1 QS 015/1 Session
2012/2013
(b) the value of p Hence, by substituting = 1, show that √3 is approximately
4 2
equal to 157.
128
9. Given ( ) = ln(2 + 3) and ( ) = −3.
2
(a) Show that ( ) is a one-to-one function algebraically. CHOW CHOON WOOI
(b) Find ( ⃘ )( ) and ( ⃘ )( ). Hence, state the conclusion about the results.
(c) Sketch the graphs of ( ) and ( ) on the same axes. Hence, state the
domain and range of ( ).
10. Given
223
= [1 5 4]
314
(a) Find the determinant of matrix .
(b) Find the minor, cofactor and adjoint of matrix .
(c) Given ( ( )) = | | where is 3 x 3 identity matrix, show that −1 =
1 ( ). Hence, find −1 .
| |
(d) By using −1 in part ( ), solve the following simultaneous equations.
2 + 2 + 3 = 49
+ 5 + 4 = 74
3 + + 4 = 49
END OF QUESTION PAPER
Page 3
6
PSPM 1 QS 015/1 Session
2012/2013
1. Find the value of x which satisfies the equation
2(5 − ) − 2( − 2) = 3 − 2(1 + )
SOLUTION
2(5 − ) − 2( − 2) = 3 − 2(1 + ) CHOW CHOON WOOI
(5 − )
2 ( − 2) = 3 − 2(1 + )
2 (5− ) + 2(1 + ) = 3
( −2)
= → =
(5 − )(1 + )
2 ( − 2) = 3
(5 − )(1 + ) = 23
( − 2)
(5 − )(1 + )
( − 2) = 8
(5 − )(1 + ) = 8( − 2)
5 + 5 − − 2 = 8 − 16
5 + 4 − 2 = 8 − 16
0 = 2 + 8 − 4 − 16 − 5
2 + 8 − 4 − 16 − 5 = 0
2 + 4 − 21 = 0
( + 7)( − 3) = 0
( + 7) = 0 or ( − 3) = 0
= −7 or = 3
Checking
2(5 − ) − 2( − 2) = 3 − 2(1 + )
When = −7
2 [5 − (−7)] − 2(−7 − 2) = 3 − 2(1 − 7)
≠ −7
When = 3
2 (5 − 3) − 2(3 − 2) = 3 − 2(1 + 3)
2 (2) − 2 (1) = 3 − 2(4)
1−0=3−2
1 = 1√
∴ = 3
Page 4
7
PSPM 1 QS 015/1 Session
2012/2013
2. Determine the solution set of the inequality CHOW CHOON WOOI
11
2 − 1 < + 2
SOLUTION
11
2 − 1 < + 2
11
2 − 1 − + 2 < 0
1( + 2) − 1(2 − 1)
(2 − 1)( + 2) < 0
+ 2 − 2 + 1
(2 − 1)( + 2) < 0
− + 3
(2 − 1)( + 2) < 0
− + 3 = 0 2 − 1 = 0 + 2 = 0
= 3
= 1 = −2
− + 3
2 − 1 2 1 1 (3, ∞)
+ 2 (−2, 2) (2 , 3) -
− + 3 (−∞, −2) +
(2 − 1)( + 2) + + + +
- -+ -
- ++
-+ +
1
∴ ℎ (−2, 2) ∪ (3, ∞)
Page 5
8
PSPM 1 QS 015/1 Session
2012/2013
3. Given + 2, − 4, − 7 are the first three terms of a geometric series. Determine the
value of . Hence, find the sum to infinity of the series.
SOLUTION
+ 2, − 4, − 7 … CHOW CHOON WOOI
− 4 − 7
+ 2 = − 4
( − 4)( − 4) = ( − 7)( + 2)
2 − 4 − 4 + 16 = 2 + 2 − 7 − 14
2 − 8 + 16 = 2 − 5 − 14
16 + 14 = −5 + 8
3 = 30
= 10
When = 10 , the sequence is
10 + 2, 10 − 4, 10 − 7 …
12, 6, 3 …
= 12, = 6 = 1
12 2
∞ = 1 −
12
∞ = 1 − (21)
12
∞ = (21)
∞ = 24
Page 6
9
PSPM 1 QS 015/1 Session
2012/2013
4. Given a complex number = 1 − √3 . Determine the value of if ̅ ̅ 2̅ = 1 .
̅
SOLUTION
= 1 − √3 ̅ = 1 + √3
̅ ̅2̅ = 1 CHOW CHOON WOOI
̅
̅̅̅̅̅̅̅̅̅̅̅̅̅2̅ 1
(1 − √3 ) = ( )
1 + √3
(̅̅1̅̅−̅̅̅√̅̅3̅̅ ̅)̅(̅1̅̅̅−̅̅̅√̅̅3̅ ̅ )̅ =
1 + √3
1̅̅̅−̅̅̅2̅√̅̅3̅̅ ̅ ̅+̅̅̅3̅ ̅ 2̅ =
1 + √3
1̅̅̅−̅̅̅2̅√̅̅3̅̅ ̅ ̅+̅̅̅3̅(̅̅−̅̅1̅̅) =
1 + √3
̅1̅̅−̅̅̅2̅̅√̅̅3̅ ̅ ̅−̅̅̅3̅ =
1 + √3
−̅̅̅2̅̅−̅̅̅2̅̅√̅̅3̅̅ =
1 + √3
−2 + 2√3 =
1 + √3
= (−2 + 2√3 )(1 + √3 )
= −2 − 2√3 + 2√3 + 6 2
= −2 + 6(−1)
= −8
Page 8
10
PSPM 1 QS 015/1 Session
2012/2013
5. (a)
Matrix is given as [−34 −41]. Show that 2 = 7 − 8 , where is the 2 x 2
identity matrix. Deduce that −1 = 7 − 1 .
88
+ 1 −1 1 CHOW CHOON WOOI
(b) Given matrix = [ 3 2 4 ] and | | = 27. Find the value of , where
−1 0 + 2
is an integer.
SOLUTION
5(a)
= [−34 −41]
2 = [−34 −41] [−34 −41]
2 = [−192+−416 −4 3+−164]
2 = [−1238 −207]
7 − 8 = 7 [−34 −41] − 8 [10 01]
7 − 8 = [−2218 −287] − [80 08]
7 − 8 = [−1238 −207]
∴ 2 = 7 − 8
2 = 7 − 8
2 − 7 = −8
( − 7 ) = −8
−1 = − 1 ( − 7 )
8
−1 = − 1 + 7
8 8
Page 9
11
PSPM 1 QS 015/1 Session
2012/2013
−1 = 7 − 1
8 8
5(b)
+ 1 −1 1 CHOW CHOON WOOI
= [ 3 2 4 ]
−1 0 + 2
| | = 27
| | = +( + 1) |02 4 2| − (−1) |−31 4 2| + (1) |−31 02|
+ +
| | = +( + 1)[(2 + 4) − (0)] + [(3 + 6) − (−4)] + [(0) − (−2)]
| | = ( + 1)(2 + 4) + (3 + 6 + 4) + 2
| | = 2 2 + 4 + 2 + 4 + 3 + 6 + 4 + 2
| | = 2 2 + 9 + 16
2 2 + 9 + 16 = 27
2 2 + 9 − 11 = 0
(2 + 11)( − 1) = 0
= − 11 = 1
2
Since is an integer, ∴ = 1
Page 10
12
PSPM 1 QS 015/1 Session
2012/2013
6. The functions and are defined as ( ) = 3 +4, ≠ 2 and ( ) = 3 − .
−2
(a) Find −1( ) and −1( ).
(b) Evaluate ( ⃘ −1)(3).
(c) If ( ⃘ −1)( ) = 2, find the value of . CHOW CHOON WOOI
3
SOLUTION
6(a) ( ) = 3 −
3 + 4 = 3 −
= 3 −
( ) = − 2 −1( ) = 3 −
3 + 4
= − 2
( − 2) = 3 + 4
− 2 = 3 + 4
− 3 = 4 + 2
( − 3) = 4 + 2
4 + 2
= − 3
−1 ( ) = 4 + 2
− 3
6(b) −1( ) = 4+2
( ) = 3 +4
−3
−2
−1( ) = 3 −
( ) = 3 −
( ⃘ −1)( ) = [ −1( )]
= [3 − ]
3(3 − ) + 4
= (3 − ) − 2
Page 11
13
PSPM 1 QS 015/1 Session
2012/2013
9 − 3 + 4
= 3 − − 2 Page 12
13 − 3
= 1 −
( ⃘ −1)(3) = 13 − 3(3) CHOW CHOON WOOI
1 − (3)
( ⃘ −1)(3) = 13 − 9
−2
( ⃘ −1)(3) = −2
6(c) −1( ) = 4+2
( ) = 3 +4
−3
−2
( ) = 3 − −1( ) = 3 −
( ⃘ −1)( ) = 2
3
( ⃘ −1)( ) = [ −1( )]
4 + 2
= [ − 3 ]
4 + 2
= 3 − ( − 3 )
4 + 2 2
3 − ( − 3 ) = 3
4 + 2 2
− 3 = 3 − 3
4 + 2 7
− 3 = 3
3(4 + 2 ) = 7( − 3)
12 + 6 = 7 − 21
= 33
14
PSPM 1 QS 015/1 Session
2012/2013
7. (a)
(b) Solve | 2 − − 3| = 3.
Find the solution set of the inequality 2 2+9 −4 < 4.
+2
SOLUTION or 2 − − 3 = −3 CHOW CHOON WOOI
7(a) or 2 − = 0
or ( − 1) = 0
| 2 − − 3| = 3 or = 0 = 1
2 − − 3 = 3
2 − − 6 = 0
( − 3)( + 2) = 0
= 3 = −2
7(b)
2 2 + 9 − 4
<4
+ 2
2 2 + 9 − 4
+ 2 − 4 < 0
(2 2 + 9 − 4) − 4( + 2) <0
+ 2
2 2 + 9 − 4 − 4 − 8 <0
+ 2
2 2 + 5 − 12 <0
+ 2
(2 − 3)( + 4) <0
+ 2
2 − 3 = 0 + 4 = 0 + 2 = 0
= −2
= 3 = −4
2
Page 13
15
PSPM 1 QS 015/1 Session
2012/2013
2 − 3 (−∞, −4) (−4, −2) 3 3
- - (−2, 2) (2 , ∞)
+ 4 - +
- - - +
+ 2 - +
(2 − 3)( + 4) ++
+ 2 ++ CHOW CHOON WOOI
-+
3
∴ ℎ solution set { : < −4 ∪ −2 < < }
2
Page 14
16
PSPM 1 QS 015/1 Session
2012/2013
8. The first four terms of a binomial expansion (1 + ) is
1 + − 1 2 + 3 + ⋯
2
Find
(a) the values of a and n where ≠ 0. CHOW CHOON WOOI
(b) the value of p Hence, by substituting = 1, show that √3 is approximately
42
equal to 157.
128
SOLUTION
8(a)
Given that
(1 + ) = 1 + − 1 2 + 3 + ⋯
2
From binomial expansion
(1 + ) = 1 + ( )( )1 + ( − 1) ( )2 + ( − 1)( − 2) ( )3 + ⋯
( 2! ) ( 3! )
(1 + ) = 1 + + ( − 1) 2 2 + ( − 1)( − 2) 3 3 + ⋯
26
1 + − 1 2 + 3 + ⋯ = 1 + + ( − 1) 2 2 + ( − 1)( − 2) 3 3 + ⋯
2 2 6
Coefficient of :
= 1 ...................... (1)
Coefficient of 2:
( − 1) 2 = − 1 = 1
2 2
( − 1) 2 = −1
( − 1) = −1
( − 1) = −1 ................(2)
(2) ( −1) = −1
(1) 1
( − 1)
= −1
− 1 = −
2 = 1
Page 15
17
PSPM 1 QS 015/1 Session
2012/2013
1 CHOW CHOON WOOI
= 2 Page 16
From (1)
= 1
1
(2) = 1
= 2
8(b)
Compare coefficient of 3:
( − 1)( − 2) 3 =
6
(12) [(12) − 1] [(12) − 2] (2)3
6
=
(12) (− 12) (− 32) (8)
6
=
24
8 = 6
6 = 3
1
= 2
(1 + 1 = 1 + − 1 2 + 1 3 + ⋯
2 2
2 )2
When = 1
4
1 1 1 12 1 13
12
[1 + 2 (4)] = 1 + 4 − 2 (4) + 2 (4) + ⋯
1
12 1 1 1 1 1
[1 + 2] = 1 + 4 − 2 (16) + 2 (64) + ⋯
1
32 1 1 1
[2] ≈ 1 + 4 − 32 + 128
18
PSPM 1 QS 015/1 Session
2012/2013
1
3 2 1(128) + 1(32) − 1(4) + 1
[2] ≈
128
1 CHOW CHOON WOOI
3 2 157
[2] ≈ 128
√3 157
2 ≈ 128
Page 17
19
PSPM 1 QS 015/1 Session
2012/2013
9. Given ( ) = ln(2 + 3) and ( ) = −3.
2
(a) Show that ( ) is a one-to-one function algebraically.
(b) Find ( ⃘ )( ) and ( ⃘ )( ). Hence, state the conclusion about the results.
(c) Sketch the graphs of ( ) and ( ) on the same axes. Hence, state the CHOW CHOON WOOI
domain and range of ( ).
SOLUTION
9(a)
( ) = ln(2 + 3)
( 1) = ln(2 1 + 3)
( 2) = ln(2 2 + 3)
Let ( 1) = ( 2)
ln(2 1 + 3) = ln(2 2 + 3)
2 1 + 3 = 2 2 + 3
2 1 = 2 2
1 = 2
Since 1 = 2, therefore ( ) is a one-to-one function.
9(b)
( ) = ln(2 + 3), ( ) = −3
2
( ⃘ )( ) = [ ( )]
− 3
= [ 2 ]
− 3
= ln [2 ( 2 ) + 3]
= ln[ − 3 + 3]
Page 18
20
PSPM 1 QS 015/1 Session
2012/2013
= ln[ ]
=
= ln = CHOW CHOON WOOI
( ⃘ )( ) = [ ( )] ln(2 +3) = 2 + 3
= [ (2 + 3)]
ln(2 +3) − 3
=2
(2 + 3) − 3
=2
=
Conclusion
Since ( ) = ( ) = , therefore −1( ) = ( ) and −1( ) = ( ).
9(c)
3 y
= − 2
( )
( )
3
= − 2
Page 19
21
PSPM 1 QS 015/1 Session
2012/2013
= (− , ∞) =(−∞, ∞)
CHOW CHOON WOOI
Page 20
22
PSPM 1 QS 015/1 Session
2012/2013
10. Given
223
= [1 5 4]
314
(a) Find the determinant of matrix .
(b) Find the minor, cofactor and adjoint of matrix . CHOW CHOON WOOI
(c) Given ( ( )) = | | where is 3 x 3 identity matrix, show that −1 =
1 ( ). Hence, find −1 .
| |
(d) By using −1 in part ( ), solve the following simultaneous equations.
2 + 2 + 3 = 49
+ 5 + 4 = 74
3 + + 4 = 49
SOLUTION
10(a)
223
= [1 5 4]
314
| | = (2) |15 44| − (2) |31 44| + (3) |31 15|
= (2)(20 − 4) − (2)(4 − 12) + (3)(1 − 15)
= (2)(16) − (2)(−8) + (3)(−14)
= 32 + 16 − 42
=6
10(b)
|15 44| |13 44| |13 15|
, = |21 34| |32 34| |23 21|
[|25 43| |12 34| |12 25|]
(20 − 4) (4 − 12) (1 − 15)
= [ (8 − 3) (8 − 9) (2 − 6) ]
(8 − 15) (8 − 3) (10 − 2)
Page 21
23
PSPM 1 QS 015/1 Session
2012/2013
16 −8 −14
= [ 5 −1 −4 ] −1 =
−7 5 8
+ 11 − 12 + 13 CHOW CHOON WOOI
, = [− 21 + 22 − 23]
− 32 + 33
+ 31
+(16) −(−8) +(−14)
= [ −(5) +(−1) −(−4) ]
+(−7) −(5) +(8)
16 8 −14
= [−5 −1 4 ]
−7 −5 8
, =
16 8 −14
= [−5 −1 4 ]
−7 −5 8
16 −5 −7
= [ 8 −1 −5]
−14 4 8
10(c)
( ( )) = | |
−1 ( ( )) = −1| |
( ( )) = −1| |
( ( )) = −1| |
−1| | = ( ( ))
−1 = 1 ( ( ))
| |
−1 = 1 16 −5 −7
6 [8 −1 −5]
4
−14 8
Page 22
24
PSPM 1 QS 015/1 Session
2012/2013
16 −5 −7 CHOW CHOON WOOI
6 66
= 8 −1 −5
6 66
−14 4 8
[ 6 6 6]
8 −5 −7
366
= 4 −1 −5
366
−7 2 4
[3 3 3]
10(d) =
−1 = −1
2 + 2 + 3 = 49
+ 5 + 4 = 74 = −1
3 + + 4 = 49 = −1
2 2 3 49
[1 5 4] [ ] = [74]
3 1 4 49
8 −5 −7 8 −5 −7
3 6 6 2 2 3 3 6 6 49
4 −1 −5 [1 5 4] [ ] = 4 −1 −5 [74]
36 6 3 1 4 36 6 49
−7 2 4 −7 2 4
[3 3 3] [3 3 3]
8 −5 −7
3 6 6 49
[ ] = 4 −1 −5 [74]
36 6 49
−7 2 4
[3 3 3]
71
= 6
73
6
1
3
∴ = , = , =
Page 23
25
QS 015/2 CHOW CHOON WOOI
Matriculation Programme
Examination
Semester 1
Session 2012/2013
26
PSPM 1 QS 015/2 Session 2012/2013
1 + , < 1
1. Given that ( ) = { 1, = 1
2 − , > 1
Find lim f (x) and lim f (x) . Does the lim f (x) exist? State your reason.
x →1− x →1+ x→1
2. Prove that 1 + tan 2 tan = sec 2 .
3. Find the following limits: CHOW CHOON WOOI
2x2 + x − 4
(a) lim
x→ 1− x2
(b) lim 3 − x + 7
x→2 x2 − 4
4. Express 2 3 −7 2 +17 −19 in the form of partial fractions.
2 2 −7 +6
5. (a) Given that ( ) = | 2− −2| , ≠ 0, 2
{ 2−2
0, = 2
Find the lim f (x) . Is ( ) continuous at = 2?
x→2
+ 6 , < 4
(b) A function ( ) is defined by ( ) = { 2 + 2 , 4 ≤ < 6
2 − , ≥ 6
Determine the values of the constants and if ( ) is continuous.
6. The polynomial ( ) = 2 3 + 2 + − 24 has a factor ( – 2) and a remainder
15 when divided by ( + 3).
(a) Find the values of a and b.
(b) Factorise ( ) completely and find all zeroes of ( ).
7. Given ( ) = 3 sin − 2 cos .
(a) Express ( ) in the form of ( − ), where > 0, 0 ≤ ≤ .
2
Hence, find the maximum and minimum values of ( ).
(b) Solve ( ) = √3 0° ≤ ≤ 360°.
2
Page 2
27
PSPM 1 QS 015/2 Session 2012/2013
8. (a) Given that = 1 .
√2 +1
i. By using the first principle of derivative, find .
ii. Find 2 2 .
(b) Find of the following: CHOW CHOON WOOI
i. = 2 tan
ii. = sec
9. (a) A conical tank is of height 12m and surface diameter 8m. Water is pumped
into the tank at the rate of 50 3/ . How fast is the water level increasing
when the depth of the water is 6m?
(b) A cylindrical container of radius and height h has a constant volume . The
cost of the materials for the surface of both of its ends is twice the cost of its
sides. State ℎ in terms of and . Hence, find h and in terms of such that
the cost is minimum.
10. (a) Given 3 2 − + 2 = 3. By using implicit differentiation,
i. Find the values of at = 1.
ii. Show that (6 − ) 2 + 6 ( 2 − 2 + 2 = 0.
2
)
(b) Consider the parametric equations
= 3 − 2, = 3 + 2 where ≠ 0.
i. Show that = 1 − 3 24+2.
ii. Find 2 when = 1.
2
END OF QUESTION PAPER Page 3
28
PSPM 1 QS 015/2 Session 2012/2013
1 + , < 1
1. Given that ( ) = { 1, = 1
2 − , > 1
Find lim f (x) and lim f (x) . Does the lim f (x) exist? State your reason.
x →1− x →1+ x→1
SOLUTION
1 + , < 1 CHOW CHOON WOOI
( ) = { 1, = 1
2 − , > 1
lim f (x) = lim (1+ ex )
x →1− x→1−
= (1+ e1)
= 1+ e
lim f (x) = lim (2 − x)
x →1+ x →1+
=2−1
=1
Since lim f (x) lim f (x) . Therefore lim f (x) does not exist.
x →1− x →1+ x→1
Page 4
29
PSPM 1 QS 015/2 Session 2012/2013
2. Prove that 1 + tan 2 tan = sec 2 .
SOLUTION
sin 2 sin cos( − ) = cos cos + sin sin CHOW CHOON WOOI
1 + tan 2 tan = 1 + (cos2 ) (cos ) cos(2 − ) = cos 2 cos + sin 2 sin
sin 2 sin
= 1 + (cos2 cos )
cos2 cos + sin 2 sin
= cos2 cos
cos(2 − )
= cos2 cos
cos( )
= cos2 cos
1
= cos2
= sec 2 .
Page 5
30
PSPM 1 QS 015/2 Session 2012/2013
Page 6
3. Find the following limits:
(a) lim 2x2 + x − 4
x→ 1− x2
(b) lim 3− x+7
x→2
x2 − 4
SOLUTION CHOW CHOON WOOI
3(a)
2x2 + x − 4
lim 2x2 + x − 4 = lim x2
1− x2 1− x2
x→ x→
x2
2 + 1 − 4
x x2
= lim
x→ 1
x2 −1
= 2+0−0
0 −1
= −2
3(b)
lim 3 − x + 7 = lim 3 − x + 7 . 3 + x + 7
x→2 x2 − 4 x→2 x2 − 4 3 + x + 7
= lim 9 − (x + 7)
x→2 (x + 2)(x − 2)(3 + x + 7)
= lim 2−x
x→2 (x + 2)(x − 2)(3 + x + 7)
= lim − (x − 2)
x→2 (x + 2)(x − 2)(3 + x + 7)
= lim −1
x→2 (x + 2)(3 + x + 7 )
31
PSPM 1 QS 015/2 Session 2012/2013
= −1 CHOW CHOON WOOI
(2 + 2)(3 + 2 + 7)
= −1
(4)(3 + 9)
= −1
24
Page 7
32
PSPM 1 QS 015/2 Session 2012/2013
4. Express 2 3 −7 2 +17 −19 in the form of partial fractions.
2 3 −7 +6
SOLUTION
2 3 −7 2+17 −19 ➔ Improper fraction
2 2 −7 +6
x CHOW CHOON WOOI
2x2 − 7x + 6 2x3 − 7x2 +17x −19
2x3 − 7x2 + 6x
11x −19
2 3 − 7 2 + 17 − 19 11x −19
= +
2 2 − 7 + 6 2x2 − 7x + 6
2 3 − 7 2 + 17 − 19 11x − 19
= + (2 − 3)( − 2)
2 2 − 7 + 6
11x − 19
(2 − 3)( − 2) = (2 − 3) + ( − 2)
11x − 19 ( − 2) + (2 − 3)
(2 − 3)( − 2) = (2 − 3)( − 2)
11x − 19 = ( − 2) + (2 − 3)
ℎ = 2
11(2) − 19 = [(2) − 2] + [(2(2) − 3)]
3 = [0] + [(1)]
= 3
3 3
ℎ = 2
33
11 (2) − 19 = [(2) − 2] + [(2 (2) − 3)]
51
− 2 = [− 2] + [(0)]
= 5
11x − 19 53
(2 − 3)( − 2) = (2 − 3) + ( − 2)
2 3 − 7 2 + 17 − 19 11x − 19
= + (2 − 3)( − 2)
2 2 − 7 + 6
2 3 − 7 2 + 17 − 19 53
= + (2 − 3) + ( − 2)
2 2 − 7 + 6
Page 8
33
PSPM 1 QS 015/2 Session 2012/2013
5. (a) Given that ( ) = | 2− −2| , ≠ 0, 2
{ 2−2
0, = 2
Find the lim f (x) . Is ( ) continuous at = 2?
x→2
+ 6 , < 4 CHOW CHOON WOOI
(b) A function ( ) is defined by ( ) = { 2 + 2 , 4 ≤ < 6
2 − , ≥ 6
Determine the values of the constants and if ( ) is continuous.
SOLUTION
5(a)
| 2 − − 2| ≠ 0, 2
( ) = { 2 − 2 , = 2
0,
lim f (x) = lim x2 − x − 2
x→2− x→2− x2 − 2x
(x +1)(x − 2)
= lim
x→2− x(x − 2)
= lim (x + 1)[−(x − 2)]
x→2− x(x − 2)
= lim − (x +1)
x→2− x
= − (2 +1)
2
=−3
2
lim f (x) = lim x2 − x − 2
x→2+ x→2+ x2 − 2x
(x +1)(x − 2)
= lim
x→2+ x(x − 2)
Page 9
34
PSPM 1 QS 015/2 Session 2012/2013
Page 10
= lim (x + 1)(x − 2)
x→2+ x(x − 2)
= lim x +1
xx→2+
= 2+1 CHOW CHOON WOOI
2
=3
2
lim f (x) lim f (x)
x→2− x→2+
lim f (x) does not exist
x→2
f (x) discontinuous at x = 2
5(b)
+ 6 , < 4
( ) = { 2 + 2 , 4 ≤ < 6
2 − , ≥ 6
f is continuous at x = 4
lim f (x) exists.
x→4
lim f (x) = lim f (x)
x→4− x→4+
lim x + 6 = lim x2 + 2
x→4− x→4+
(4) + 6 = (4)2 + 2
4 = 12
=3
f is continuous at x = 6
lim f (x) exists.
x→6
lim f (x) = lim f (x)
x→6− x→6+
lim x2 + 2 = lim 2 − x
x→6− x→6+
35
PSPM 1 QS 015/2 Session 2012/2013
(6)2 + 2 = 2 − (6)
38 = 2 − 6 CHOW CHOON WOOI
6 = −36
= −6
∴ = 3, = −6
Page 11
36
PSPM 1 QS 015/2 Session 2012/2013
6. The polynomial ( ) = 2 3 + 2 + − 24 has a factor ( – 2) and a remainder 15
when divided by ( + 3).
a. Find the values of a and b.
b. Factorise ( ) completely and find all zeroes of ( ).
SOLUTION CHOW CHOON WOOI
6(a)
(2) = 0
(−3) = 15
( ) = 2 3 + 2 + − 24
(2) = 2(2)3 + (2)2 + (2) − 24 = 0
16 + 4 + 2 − 24 = 0
4 + 2 = 8 .................(1)
(−3) = 2(−3)3 + (−3)2 + (−3) − 24 = 15
−54 + 9 − 3 − 24 = 15
9 − 3 = 93
3 − = 31.................(2)
(2) 2
6 − 2 = 62.................(3)
(1)+(2)
10 = 70
= 7
= −10
Page 12
37
PSPM 1 QS 015/2 Session 2012/2013
6(b) CHOW CHOON WOOI
P(x) = 2x3 + 7x2 −10x − 24
= (x − 2)Q(x)
2x 2 + 11x + 12
x − 2 2x3 + 7x 2 − 10x − 24
2x3 − 4x2
11x 2 − 10x − 24
11x 2 − 22x
12x − 24
12x − 24
0
P(x) = (x − 2)(2x2 + 11x + 12)
= (x − 2)(2x + 3)(x + 4)
when P(x) = 0
(x − 2)(2x + 3)(x + 4) = 0
x = 2 , x = − 3 , x = −4
2
The zeroes are 2 , − 3 and − 4
2
Page 13
38
PSPM 1 QS 015/2 Session 2012/2013
7. Given ( ) = 3 sin − 2 cos .
a. Express ( ) in the form of ( − ), where > 0, 0 ≤ ≤ .
2
Hence, find the maximum and minimum values of ( ).
b. Solve ( ) = √3 0° ≤ ≤ 360°. CHOW CHOON WOOI
2
SOLUTION
a) 3sin − 2 cos = R sin( − )
= R sin cos − R cos sin
R cos = 3 (1)
R sin = 2 (2)
(1)2 + (2)2 :
R 2 cos 2 + R 2 sin 2 = 32 + 22
R2 (1) = 13
R = 13
(2) (1) :
R sin = 2
R cos 3
tan = 2
3
= 0.588
3sin − 2 cos = 13 sin( − 0.588)
−1 sin( − 0.588) 1
− 13 13 sin( − 0.588) 13
− 13 3sin − 2 cos 13
− 13 f ( ) 13
Minimum value of f ( ) = − 13
Maximum value of f ( ) = 13
Page 14
39
PSPM 1 QS 015/2 Session 2012/2013
b) f ( ) = 13 13
2 2
13 sin( − 0.588) =
sin( − 0.588) = 1
2
− 0.588 = 0.785 , − 0.785 CHOW CHOON WOOI
= 1.373 , 2.945
= 78.70 , 168.70
Page 15
40
PSPM 1 QS 015/2 Session 2012/2013
8. (a) Given that = 1 . CHOW CHOON WOOI
√2 +1
i. By using the first principle of derivative, find .
ii. Find 2 2 .
(b) Find of the following:
iii. = 2 tan
iv. = sec
SOLUTION
(a) y = 1
2x +1
i) Let f (x) = 1
2x +1
f (x + h) = 1
2(x + h) +1
f (x) = lim f (x + h) − f (x)
h→0 h
dy = lim 1− 1
dx h→0 2(x + h) + 1 2x +1
h
= lim 2x +1 − 2(x + h) +1
h→0 2(x + h) +1 2x + 1
h
= lim 2x + 1 − 2x + 2h + 1 2x + 1 + 2x + 2h + 1
h→0 h 2(x + h) + 1 2x + 1 2x + 1 + 2x + 2h + 1
= lim (2x +1) − (2x + 2h +1)
h→0 h 2(x + h) +1 2x +1( 2x +1 + 2x + 2h +1)
= lim − 2h
h→0 h 2(x + h) +1 2x +1( 2x +1 + 2x + 2h +1)
= lim −2
h→0 2(x + h) + 1 2x +1( 2x +1 + 2x + 2h +1)
Page 16
41
PSPM 1 QS 015/2 Session 2012/2013
Page 17
= −2
2x +1 2x +1( 2x +1 + 2x +1)
= −2
(2x +1)(2 2x +1)
=− 1 CHOW CHOON WOOI
3
(2x + 1) 2
ii) dy −3
dx = −(2x + 1) 2
d2y = 3 (2x −5
dx2 2 + 1) 2 (2)
=3
5
(2x + 1) 2
b i) y = e2x tan x
dy = e2x (sec2 x) + tan x(2e2x )
dx
= e2x (sec 2 x + 2 tan x)
ii) y = xsec x
ln y = ln xsec x
ln y = sec x ln x
1 dy = sec x 1 + (ln x)(sec x tan x)
y dx x
dy = y sec x + x(ln x) sec x tan x
dx x
= x sec x sec x1 + x(ln x) tan x
x
42
PSPM 1 QS 015/2 Session 2012/2013
9. (a) A conical tank is of height 12m and surface diameter 8m. Water is pumped
into the tank at the rate of 50 3/ . How fast is the water level increasing
when the depth of the water is 6m?
(b) A cylindrical container of radius and height h has a constant volume . The CHOW CHOON WOOI
cost of the materials for the surface of both of its ends is twice the cost of its
sides. State ℎ in terms of and . Hence, find h and in terms of such that
the cost is minimum.
SOLUTION
9(a) 4
8m
4m
12 m r r ℎ
h 12 4 = 12
h ℎ
= 3
= 50 3/ [ ℎ =? ℎ ℎ = 6]
ℎ ℎ
= .
= 1 2ℎ
3
1 ℎ2
= 3 (3) ℎ
1 ℎ3
= 3 9
= 1 ℎ3
27
= 1 ℎ2 = ℎ2
ℎ 9 9
Page 18
43
PSPM 1 QS 015/2 Session 2012/2013
ℎ 9 r CHOW CHOON WOOI
= ℎ2
ℎ ℎ = 2 ℎ
= .
ℎ 9 h
= ( ℎ2) . (50)
ℎ 450
= ℎ2
ℎ ℎ = 6
ℎ 450
= (6)2
ℎ 450
= 36
ℎ 25
= 2 /
9(b)
r
h
2
2
V = r2h
h= V
r2
Page 19
44
PSPM 1 QS 015/2 Session 2012/2013
The cost,
C = 2 r2 (2) + 2 rh(1)
= 4 r2 + 2 r V 2
r
C = 4 r 2 + 2V
r
dC = 8 r − 2V CHOW CHOON WOOI
dr r 2
when dC = 0
dr
8 r − 2V =0
r2
8 r = 2V
r2
r3 = V
4
1
r = V 3
4
d 2C = 8 + 4V
dr 2 r3
1
when r = V 3 ,
4
d 2C = 8 + 4V = 24 0 (min)
dr 2 V
4
1
r = V 3
4
1
h = V 2 =V = 16V 3
r 2
V 3
4
Page 20
45
PSPM 1 QS 015/2 Session 2012/2013
10 (a) Given 3 2 − + 2 = 3. By using implicit differentiation,
i. Find the values of at = 1.
ii. Show that (6 − ) 2 + 6 ( 2 − 2 + 2 = 0.
2
)
(b) Consider the parametric equations CHOW CHOON WOOI
= 3 − 2, = 3 + 2 where ≠ 0.
iii. Show that = 1 − 3 24+2.
iv. Find 2 when = 1.
2
SOLUTION
10[a(i))]
3 2 − + 2 = 3
6 − [ + ] + 2 = 0
6 − − + 2 = 0
(6 − ) = − 2
− 2
= 6 −
ℎ = 1
3 2 − (1) + (1)2 = 3
3 2 − + 1 = 3
3 2 − − 2 = 0
3 2 − − 2 = 0
(3 + 2)( − 1) = 0
= − 2 or = 1
3
Page 21
46
PSPM 1 QS 015/2 Session 2012/2013
Page 22
6 y dy − x dy + y(−1) + 2x = 0
dx dx
dy (6 y − x) = y − 2x
dx
dy = y − 2x
dx 6 y − x
For x = 1, y = − 2 : CHOW CHOON WOOI
3
− 2 − 2(1) =8
dy = 3
dx 6 − 2 −1 15
3
For x = 1, y = 1 :
dy = 1 − 2(1) = − 1
dx 5
6(1) −1
10[a(ii))]
dy (6 y − x) = y − 2x
dx
dy 6 dy − 1 + (6 y − x) d2y = dy − 2
dx dx dx 2 dx
6 dy 2 − dy + (6 y − x) d2y − dy + 2 = 0
dx dx dx 2 dx
(6 y − x) d2y + 6 dy 2 − 2 dy + 2 = 0
dx 2 dx dx
10(b)
x = 3t − 2 , y = 3t + 2
tt
i) dx = 3+ 2 = 3t 2 + 2
dt t2 t2
dy = 3 − 2 = 3t 2 − 2
dt t 2 t2
dy
dy = dt
dx dx
dt
47
PSPM 1 QS 015/2 Session 2012/2013
3t 2 − 2
= t2
3t 2 + 2
t2
= 3t 2 − 2
3t 2 + 2
1 CHOW CHOON WOOI
3t 2 + 2 3t 2 − 2
3t 2 + 2
−4
dy = 1 − 4
dx 3t 2 + 2
ii) d dy = d 1 − 3t 4 2
dt dx dt 2+
= d [1− 4(3t2 + 2)−1]
dt
= 4(3t 2 + 2)−2 (6t)
= 24t
(3t 2 + 2)2
d2y = d dy 24t = 24t 3
dt dx = (3t 2 + 2)2
dx2 dx 3t 2 + 2 (3t 2 + 2)3
dt t 2
when t = 1,
d 2 y = 24(1)3 = 24
dx2 (3(1)2 + 2)3 125
Page 23
48
2013/2014
49
CHOW CHOON WOOI
QS 015/1 CHOW CHOON WOOI
Matriculation Programme
Examination
Semester I
Session 2013/2014
50