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.

3,036.

From the diagram above. ABC is a triangle inscribed in a circle center O. ∠ACB = 40o and |AB| = x cm. calculate the radius of the circle.

A.

\(\frac{x}{sin 40^o}\)

B.

\(\frac{x}{cos 40^o}\)

C.

\(\frac{x}{2 sin 40^o}\)

D.

\(\frac{x}{2 cos 40^o}\)

Correct answer is C

No explanation has been provided for this answer.

3,037.

From the top of a cliff 20m high, a boat can be sighted at sea 75m from the foot of the cliff. Calculate the angle of depression of the boat from the top of the cliff

A.

14.9 o

B.

15.5 o

C.

74.5 o

D.

75.1 o

Correct answer is A

\(\tan x = \frac{20}{75} = 0.267\)

\(x = \tan^{-1} 0.267 = 14.93°\)

\(\approxeq\) 14.9°

3,038.

If \(tan x = \frac{1}{\sqrt{3}}\), find cos x - sin x such that \(0^o \leq x \leq 90^o\)<

A.

\(\frac{\sqrt{3}+1}{2}\)

B.

\(\frac{2}{\sqrt{3}+1}\)

C.

\(\frac{\sqrt{3}-1}{2}\)

D.

\(\frac{2}{\sqrt{3}-1}\)

Correct answer is C

\(\cos x = \frac{\sqrt{3}}{2}\)

\(\sin x = \frac{1}{2}\)

\(\cos x - \sin x = \frac{\sqrt{3} - 1}{2}\)

3,039.

If y varies inversely as x\(^2\), how does x vary with y?

A.

x varies inversely as y2

B.

x varies inversely as √y

C.

x varies directly as y2

D.

x varies directly as y

Correct answer is B

\(y \propto \frac{1}{x^2}\)

\(y = \frac{k}{x^2}\)

\(x^2 = \frac{k}{y}\)

\(x = \frac{\sqrt{k}}{\sqrt{y}}\)

Since k is a constant, then \(\sqrt{k}\) is also a constant.

\(\therefore x \propto \frac{1}{\sqrt{y}}\)

3,040.

Simplify \(\frac{4}{x+1}-\frac{3}{x-1}\)

A.

\(\frac{x+7}{x^2 - 1}\)

B.

\(\frac{x-7}{x^2 + 1}\)

C.

\(\frac{x-7}{x^2 - 1}\)

D.

\(\frac{x-11}{x^2 - 1}\)

Correct answer is C

\(\frac{4}{x+1}-\frac{3}{x-1}\)

=\(\frac{4x - 4 - 3x - 3}{(x+1)(x-1)}=\frac{x-7}{x^2 - 1}\)