Mathematics questions and answers

Mathematics Questions and Answers

How good are you with figures and formulas? Find out with these Mathematics past questions and answers. This Test is useful for both job aptitude test candidates and students preparing for JAMB, WAEC, NECO or Post UTME.

3,896.

Evaluate \(\int \sin 3x \mathrm d x\)

A.

(2/3) cos 3x + c

B.

(1/3) cos 3x + c

C.

(-1/3) cos 3x + c

D.

(-2/3) cos 3x + c

Correct answer is C

\(\int \sin 3x \mathrm d x = - \frac{\cos 3x}{3} + c\)

= \(-\frac{1}{3} (\cos 3x) + c\)

3,897.

The slope of the tangent to the curve y = 3x\(^2\) - 2x + 5 at the point (1, 6) is

A.

4

B.

1

C.

6

D.

5

Correct answer is A

y = 3x\(^2\) - 2x + 5

Slope = \(\frac{\mathrm d y}{\mathrm d x} = 6x - 2\)

At x = 1,

Slope : 6(1) - 2 = 4.

3,898.

Find the derivative of \(y = \sin^{2} (5x)\) with respect to x.

A.

10 sin 5x cos 5x

B.

5 sin5x cos 5x

C.

2 sin 5x cos 5x

D.

15 sin 5x cos 5x

Correct answer is A

\(y = \sin^{2} (5x)\)

Let u = sin 5x

\(\frac{\mathrm d u}{\mathrm d x} = 5 \cos 5x\)

\(\therefore y = u^{2}\)

\(\frac{\mathrm d y}{\mathrm d u} = 2u\)

\(\frac{\mathrm d y}{\mathrm d x} = 2u . 5 \cos 5x\)

= \(10u \cos 5x\)

= \(10 \sin 5x \cos 5x\)

3,899.

If dy/dx = 2x - 3 and y = 3 when x = 0, find y in terms of x.

A.

2x2 - 3x

B.

x2 - 3x

C.

x2 - 3x - 3

D.

x2 - 3x + 3

Correct answer is D

dy/dx = 2x - 3
y = ∫2x - 3 dx => y = x2 - 3x + c
3 = (0)2 - 3(0) + c
=> c = 3

Thus y = x2 - 3x + 3

3,900.

A trader bought goats for N4000 each. He sold them for N180,000 at a loss of 25%. How many goats did he buy?

A.

60

B.

50

C.

45

D.

36

Correct answer is A

Let the number of goats be X
C.P of X goats = N4000X
S.P of X goats = (75/100) x 4000X = N3000X

3000X = 180,000

=> X = 180000/3000 = 60.
X = 60 goats