Rational Functions - Mathematics - Exam, Exams of Mathematics

This is the Past Exam of Mathematics which includes Rational Functions, Definite Integrals, Indefinite Integrals, Partial Fractions, Constants, Evaluate, Integration, Parts, First Order Differential etc. Key important points are: Rational Functions, Definite Integrals, Indefinite Integrals, Partial Fractions, Constants, Evaluate, Integration, Parts, First Order Differential, Separation

Typology: Exams

2012/2013

Uploaded on 02/26/2013

devkinandan
devkinandan 🇮🇳

5

(1)

103 documents

1 / 9

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
MATH 014
Examiner: Dr. T. M. Mohaupt, Extension 55177.
Time allowed: Three hours
ALL answers to Section A and the best THREE answers to Section B will be
counted. Section A carries 55% of the available marks. The marks shown against
questions, or parts of questions, indicate their relative weight. Your attention is
drawn to the Formulae Sheet which accompanies this exam paper.
Paper Code MATH 014 Page 1 of 5 CONTINUED
pf3
pf4
pf5
pf8
pf9

Partial preview of the text

Download Rational Functions - Mathematics - Exam and more Exams Mathematics in PDF only on Docsity!

MATH 014

Examiner: Dr. T. M. Mohaupt, Extension 55177.

Time allowed: Three hours

ALL answers to Section A and the best THREE answers to Section B will be counted. Section A carries 55% of the available marks. The marks shown against questions, or parts of questions, indicate their relative weight. Your attention is drawn to the Formulae Sheet which accompanies this exam paper.

SECTION A

  1. Evaluate the following indefinite integrals

(i)

∫ 5 x−^4 dx [2 marks] , (ii)

∫ (^) dx √ 5 x − 1

[2 marks] ,

(iii)

∫ x(x + 1)^8 dx [3 marks] , (iv)

∫ e−^5 x+2^ dx [3 marks].

  1. Evaluate the following definite integrals

(i)

∫ (^1)

− 1

x^2 (4x + 3) dx [2 marks] , (ii)

∫ (^27)

3

dx √ 3 x

[2 marks] ,

(iii)

∫ (^3)

0

(4x^2 − 7 x + 1) dx [3 marks] , (iv)

∫ (^) π π 2 cos(5x)^ dx^ [3 marks]^.

  1. Using partial fractions, the following rational functions can be written as

(i)

5 x − 13 (x − 7)(x + 4)

A

x − 7

B

x + 4

(ii)

4 x^2 − 3 x − 1 (x − 2)(x + 1)^2

C

x − 2

D

x + 1

E

(x + 1)^2

Compute the constants A, B, C, D, E. [5 marks]

Hence evaluate the following integrals:

(iii)

∫ (^5) x − 13

(x − 7)(x + 4)

dx ,

[2 marks]

(iv)

∫ (^5)

3

4 x^2 − 3 x − 1 (x − 2)(x + 1)^2

dx.

[3 marks]

SECTION B

(i) A car drives with a speed of 40m s. How long does it take to travel a distance of 4km? [1 marks]

(ii) A speed limit forces the driver to reduce his speed from 40 m s to 20m s. If this takes 4 seconds, what is the deceleration during this period? And what is the distance traveled during this period? [6 marks]

(iii) The car continues with a speed of 20m s for 6 minutes. What is the distance traveled during this period? [1 marks]

(iv) The driver applies the same deceleration as under (ii) to bring the car from the speed 20 m s to complete rest. How long does this take and what is the distance traveled during this period? [5 marks]

(v) What is the total distance traveled in the trip described in (i)-(iv)? How much time does the trip take? [2 marks]

(i) Solve the following second order differential equation

d^2 y dx^2

  • 3y = 0 ,

and find the particular solution where y = −2 and dy dx =

3 when x = π 6

[8 marks]

(ii) Evaluate the following integral ∫ (^0)

− π 8

sin^3 (4x) cos^2 (4x) dx

Hint: You may use the substitution u = cos(4x). [7 marks]

  1. A stone is thrown vertically upwards with initial velocity v 0 and returns to the ground after 10 seconds. The stone is modelled by a particle which experiences only gravity.

(i) Using the notation that the vertically upwards direction is denoted by y, with the origin y = 0 at ground level, show that the equation of motion for the stone is d^2 y dt^2

= −g ,

where g ≈ 10 m s 2 is the acceleration due to gravity, and t is time. [3 marks]

(ii) Find the general solution of this differential equation. [3 marks]

(iii) Compute the initial velocity v 0 and the maximal height reached by the stone. Hint: the maximal height is reached after one half of the total time. [6 marks]

(iv) If you double the initial velocity, how does this change the maximal height and the total time of the flight? [3 marks]

  1. A simple pendulum makes an angle of θ with the vertical. Its motion is approximately described by the differential equation

d^2 θ dt^2

  • k^2 θ = 0 , (1)

where t is time and k^2 = 499.

(i) Given that θ = 3 and dθ dt = 7 at t = 0, solve the above differential equation. [5 marks]

(ii) Show that your solution is identical to the function

θ(t) = 3

2 sin(^73 t + π 4 ). (2)

You may either use trigonometric identities or show that the function (2) solves the differential equation (1) and satisfies the initial conditions spec- ified in part (i). [5 marks]

(iii) Plot this function on a graph, where the horizontal axis is t and the vertical axis is θ, such that you display at least one full period of the function. Specify explicitly the period of the function. [5 marks]

Paper Code MATH 014 Page 5 of 5 END

List of Derivatives

f (x) : cxn^

c x

c xn^

cex^ c ln x sin x cos x tan x

df dx

: c nxn−^1 −

c x^2

nc xn+^

cex^

c x

cos x − sin x

cos^2 x

= sec^2 x

List of Integrals (all + C)

f (x)

∫ f (x)dx f (x)

∫ f (x)dx

(ax + b)n^

(ax + b)n+ a(n + 1)

, (n 6 = −1)

ax + b

a

ln |ax + b|

(ax + b)^2

a(ax + b)

(ax + b)(cx + d)

ad − bc

ln

∣∣ ∣∣ ∣

ax + b cx + d

∣∣ ∣∣ ∣ ,^ (ad^ −^ bc^6 = 0)

ax^2 + b

ab

arctan

(√ a b

x

) , (a, b > 0)

ax^2 − b

ab

ln

∣∣ ∣∣ ∣

ax −

b √ ax +

b

∣∣ ∣∣ ∣, (a, b >^ 0)

x ax^2 + b

2 a

ln |ax^2 + b| eax^

a

eax

sin(ax) −

a

cos(ax) cos(ax)

a

sin(ax)

Substitution

∫ f (x) dx =

∫ ( h(u)

dx du

) du , where f (x) = h(u(x)).

∫ (^) b

a

f (x)dx =

∫ (^) u(b)

u(a)

( h(u)

dx du

) du , where f (x) = h(u(x)).

Integration by parts

∫ u(x)

dv dx

dx = u(x)v(x) −

∫ (^) du

dx

v(x) dx + C.

∫ (^) b

a

u(x)

dv dx

dx = [u(x)v(x)]ba −

∫ (^) b

a

du dx

v(x) dx.

Differential Equations

Separation of Variables

Equation Solution

dy dx

= f (x) y =

∫ f (x)dx

dy dx

= ay y = eax+C^ , for y > 0.

Second order, linear, unforced (homogeneous) differential equations

Standard form:

a

d^2 y dx^2

  • b

dy dx

  • cy = 0. (1)

Characteristic equation: aα^2 + bα + c = 0. (2)

Solution of characteristic equation (2) for a 6 = 0:

α 1 , 2 =

−b ±

b^2 − 4 ac 2 a

Discriminant: D = b^2 − 4 ac.