vce mathematical methods (cas) units 3 & 4 - … · vce mathematical methods (cas) units 3...

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Neap Trial Exams are licensed to be photocopied or placed on the school intranet and used only within the confines of the school purchasing them, for the purpose of examining that school's students only. They may not be otherwise reproduced or distributed. The copyright of Neap Trial Exams remains with Neap. No Neap Trial Exam or any part thereof is to be issued or passed on by any person to any party inclusive of other schools, non-practising teachers, coaching colleges, tutors, parents, students, publishing agencies or websites without the express written consent of Neap. Copyright © 2010 Neap ABN 49 910 906 643 96–106 Pelham St Carlton VIC 3053 Tel: (03) 8341 8341 Fax: (03) 8341 8300 TEVMMU34EX1_SS_2010.FM Trial Examination 2010 VCE Mathematical Methods (CAS) Units 3 & 4 Written Examination 1 Suggested Solutions

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Page 1: VCE Mathematical Methods (CAS) Units 3 & 4 - … · VCE Mathematical Methods (CAS) Units 3 & 4 Written Examination 1 Suggested Solutions. VCE Mathematical Methods (CAS) Units 3 &

Neap Trial Exams are licensed to be photocopied or placed on the school intranet and used only within the confines of the school purchasing them, for the purpose of examining that school's students only. They may not be otherwise reproduced or distributed. The copyright of Neap Trial Exams remains with Neap. No Neap Trial Exam or any part thereof is to be issued or passed on by any person to any party inclusive of other schools, non-practising teachers, coaching colleges, tutors, parents, students, publishing agencies or websites without the express written consent of Neap.

Copyright © 2010 Neap ABN 49 910 906 643 96–106 Pelham St Carlton VIC 3053 Tel: (03) 8341 8341 Fax: (03) 8341 8300 TEVMMU34EX1_SS_2010.FM

Trial Examination 2010

VCE Mathematical Methods (CAS) Units 3 & 4

Written Examination 1

Suggested Solutions

Page 2: VCE Mathematical Methods (CAS) Units 3 & 4 - … · VCE Mathematical Methods (CAS) Units 3 & 4 Written Examination 1 Suggested Solutions. VCE Mathematical Methods (CAS) Units 3 &

VCE Mathematical Methods (CAS) Units 3 & 4 Trial Examination 1 Suggested Solutions

Copyright © 2010 Neap TEVMMU34EX1_SS_2010.FM 2

Question 1

a. y-intercept (x = 0)

A1

b. x-intercepts (y = 0)

M1

OR M1

A1

Question 2

a. ,

thus A1

(Alternatively, using the product rule directly gives , which is

equivalent to the answer above.)

f 0( ) sin2 π2---–

1–=

1–( )2 1– =

0 =

sin2 2x π2---–

1– 0=

sin2 2x π2---–

1=

2x π2---–

sin 1±=

x 0 2π,[ ]∈2x 0 4π,[ ]∈∴

2xπ2--- π

2---–

7π2

-------,∈–∴

2x π2---–

sin 1–=

2x π2---–

π2--- 3π

2------- 7π

2-------, ,–=

2x 0 2π 4π,,=

x 0 π 2π, ,=

2x π2---–

sin 1=

2x π2---–

π2--- 5π

2-------,=

2x π 3π,=

xπ2--- 3π

2-------,=

x 0π2--- π

3π2

------- 2π, , , ,=

y x2loge 1x---

x2loge x 1–( ) x2loge x( )–= = =

dydx------ 2x– loge x( ) x2 1

x---⋅–⋅ 2xloge x( ) x––= =

dydx------ 2xloge

1x---

x2 1–x

------ +=

Page 3: VCE Mathematical Methods (CAS) Units 3 & 4 - … · VCE Mathematical Methods (CAS) Units 3 & 4 Written Examination 1 Suggested Solutions. VCE Mathematical Methods (CAS) Units 3 &

VCE Mathematical Methods (CAS) Units 3 & 4 Trial Examination 1 Suggested Solutions

Copyright © 2010 Neap TEVMMU34EX1_SS_2010.FM 3

b. For stationary points we require .

gives x = 0, M1

Clearly so a stationary point exists if .

Now

Thus the stationary point occurs at . A1

Sign of the derivative test: Use suitable values such as for , choose and for

, choose .

, M1

,

∴ a maximum turning point occurs at . A1

Question 3

a. f is a parabola with turning point (2, 4).

∴ maximum value of a is 2, so f is one-to-one. A1

b. inverse M1

A1

dydx------ 0=

x 1 2loge x( )+( )– 0= loge x( ) 12---–=

x 0> loge x( ) 12---– x⇒ e

12---–

= =

y e

12---–

2

loge× 1

e

12---–

-------

=

e 1– 12---× =

12e------ =

e

12---– 1

2e------,

x e

12---–

< x e 1–=

x e

12---–

> x 1=

x e 1–= dydx------ e 1– 1 2logee 1–+[ ]×– e 1– 1 2–( )× 0>–= =

x 1= dydx------ 1 1 2loge1+[ ]×– 1 1 0<×–= =

e

12---– 1

2e------,

x y 2–( )2 4+=

x 4– y 2–( )2=

y 2– x 4–±=

y 2 x 4– (as y ∞ 2 ) i.e. domain of f ),–(∈–=

f 1– x( )∴ 2 x 4––=

Page 4: VCE Mathematical Methods (CAS) Units 3 & 4 - … · VCE Mathematical Methods (CAS) Units 3 & 4 Written Examination 1 Suggested Solutions. VCE Mathematical Methods (CAS) Units 3 &

VCE Mathematical Methods (CAS) Units 3 & 4 Trial Examination 1 Suggested Solutions

Copyright © 2010 Neap TEVMMU34EX1_SS_2010.FM 4

c. rule of

domain of

∴ graph is: A1

Question 4

a.

correct identification of f and g A1

coordinates of P A1

b. Given , then . M1

Thus . A1

f 1– f x( )( ) x=

f 1– f x( )( ) domain f ∞ 2 ),–(= =

y

x0

2

2

(2, 2)

y

xO

1.0

2.0

P

π2---π

4---

f x( ) xtan=

g x( ) 2 xcos=

π4--- 1,

y loge x( )cos( )= dydx------ x( )sin–

x( )cos------------------ x( )tan–= =

x( )tan xd∫ log– e x( )cos( )=

Page 5: VCE Mathematical Methods (CAS) Units 3 & 4 - … · VCE Mathematical Methods (CAS) Units 3 & 4 Written Examination 1 Suggested Solutions. VCE Mathematical Methods (CAS) Units 3 &

VCE Mathematical Methods (CAS) Units 3 & 4 Trial Examination 1 Suggested Solutions

Copyright © 2010 Neap TEVMMU34EX1_SS_2010.FM 5

c. Area A1

M1

(or equivalent: or ) A1

Question 5

As events A and B are independent, . A1

Also, events will be independent so we know .

From the question, .

Thus , giving M1

A1

Question 6

Multiplying by gives: M1

A1

2 x( )cos x( )tan–( ) xd0

π4---

∫ =

2 x( )sin loge x( )cos( )+[ ]0

π4---

=

2π4---

sin logeπ4---

cos + 2 0sin loge 0cos+[ ]– =

2 1

2------- loge

1

2-------

+× 2 0× loge 1( )+[ ]– =

1 loge 2( )–= 1 loge1

2-------

+ 1 12---– loge 2( )

Pr A B( ) Pr A( ) 34--- Pr A ′( )⇒ 1

4---= = =

A ′ and B ′ Pr A ′ B ′∩( ) Pr A ′( ) Pr× B ′( )=

Pr B( ) Pr A ′ B ′∩( )=

Pr B( ) 14--- 1 Pr B( )–( )= 4 Pr B( ) 1 Pr B( )–( ) 5 Pr B( )⇒ 1= =

Pr B( ) 15---=

ex 4– 5e x–=

ex

ex( )2

4ex– 5=

ex( )2

4ex– 5– 0=

ex 5–( ) ex 1+( ) 0=

ex 5 or –1, ex 1–≠=

x loge5=

Page 6: VCE Mathematical Methods (CAS) Units 3 & 4 - … · VCE Mathematical Methods (CAS) Units 3 & 4 Written Examination 1 Suggested Solutions. VCE Mathematical Methods (CAS) Units 3 &

VCE Mathematical Methods (CAS) Units 3 & 4 Trial Examination 1 Suggested Solutions

Copyright © 2010 Neap TEVMMU34EX1_SS_2010.FM 6

Question 7

We require A1

M1

A1

Question 8

M1

Equation of tangent

A1

Hence to pass through (0, 0):

A1

Question 9

a.

∴ image is (0, –1). A1

Pr T 6 T 3≥≤( ) Pr 3 T 6≤ ≤( )Pr T 3≥( )

--------------------------------=

t–50------ 1

5---+ td

3

6

∫1 Pr T 3<( )–-------------------------------- =

t2–100--------- t

5---+

3

6

1 51100---------–

--------------------------

36–100--------- 6

5---+

9–100--------- 3

5---+

49100---------

------------------------------------------------------= =

27–100--------- 3

5---+

49100---------

------------------- = 33

100--------- 100

49---------× 33

49------= =

f a( ) a2 k+=

f ′ x( ) 2x=

f ′ a( ) 2a=

y a2 k+( )– 2a x a–( )=

y 2ax a2– k+=

a2– k+ 0=

k a2=

k 0≥∴

X ′ TX B+=

x'

y'

2 0

0 1–

2

3

4–

2+=

4

3–

4–

2+ =

0

1– =

Page 7: VCE Mathematical Methods (CAS) Units 3 & 4 - … · VCE Mathematical Methods (CAS) Units 3 & 4 Written Examination 1 Suggested Solutions. VCE Mathematical Methods (CAS) Units 3 &

VCE Mathematical Methods (CAS) Units 3 & 4 Trial Examination 1 Suggested Solutions

Copyright © 2010 Neap TEVMMU34EX1_SS_2010.FM 7

b.

M1

M1

becomes

A1

∴ required image is .

Alternatively, a more elegant solution which avoids the need to find an inverse matrix is shown below:

M1

⇒ Μ1

Adding gives .

∴ required image is . A1

c. A dilation of factor 2 from the y-axis and a reflection in the y-axis A1

followed by translations of 4 units to the left and 2 upwards. A1

Note: the order of the first two transformations could be exchanged and similarly, the order of the translations is not significant, however the translations must follow the dilation and reflection.

x ′y ′

2 0

0 1–

x

y

4–

2+=

x ′y ′

4–

2– 2 0

0 1–

x

y=

12–

------ 1– 0

0 2

x ′ 4+

y ′ 2–

12–

------ 1– 0

0 2

2 0

0 1–

x

y=

1 0

0 1

x

y=

x

y

12–

------ 1– 0

0 2

x ′ 4+

y ′ 2–=∴

x∴ x ′ 4+2

-------------=

y y ′– 2+=

y∴ 2x 4–= y ′– 2+ 2x ′ 4+

2-------------

4–=

y ′ 2 x ′–=

y 2 x–=

TX B+ 2 0

0 1–

x

2x 4+

4–

2+=

2x

2x– 4+

4–

2+=

X ′∴ 2x 4–

2x– 6+=

x ′ 2x 4–=

y ′ 2x– 6+=

x ′ y ′+ 2=

x y+ 2=

Page 8: VCE Mathematical Methods (CAS) Units 3 & 4 - … · VCE Mathematical Methods (CAS) Units 3 & 4 Written Examination 1 Suggested Solutions. VCE Mathematical Methods (CAS) Units 3 &

VCE Mathematical Methods (CAS) Units 3 & 4 Trial Examination 1 Suggested Solutions

Copyright © 2010 Neap TEVMMU34EX1_SS_2010.FM 8

Question 10

a. Approximate change M1

A1

b. The gradient function at is positive and increasing. Therefore the approximation of the change is less than the exact change. A1

V x h+( ) V x( )– =

hV ′ x( ) =

V 6x3, so V ′ x( ) 18x2==

x 3, h 0.02: hV ′ x( ) 0.02V ′ 3( )= = =

0.02 18 32××=

3.24=

3.24 cm3 =

x 3=