Processing math: 100%

JAMB Mathematics Past Questions & Answers - Page 180

896.

A stone Q is tied to a point P vertically above Q by an inelastic string of length 2 meters. How high does the stone rise when the string is inclined at an angle 60^o to the vertical?

It does not rise

2 $\sqrt{3}$ meters

3 meters

1 meter

View answer & explanation

Correct answer is D

Cos 60^o = $\frac{PD}{2}$

Cos 60^o x 2 = 0.5 x 2

= 1m

897.

Find the values of x for which the expression $\frac{(x - 3)(x - 2)}{x^2 + x - 2}$

1, -2

-1, 2

2, 3

-1. -2

-2, -3

View answer & explanation

Correct answer is A

to find the values of x for which the expression is underlined, let x² + x - 2 = 0

By factorizing, we have (x + 2)(x - 1) = 0

when x + 2 = 0, when x - 1 = 0, x = -2 or x = 1

The two values are -2 and 1

898.

Express 37.05 x 0.0042 in standard form

15.561 x 10²

1.5561 x 10^-4

1.556 x 10^-1

1.5561 x 10¹

1.55 x 10¹

View answer & explanation

Correct answer is C

37.05 x 0.0042 in standard form

$\begin{array}{c|c}No. & log \\\hline 37.05 & 1.5688\\ 0.0042 & 3.6232 \\ \hline & 1.1920\end{array}$

= 0.1556

= 1.556 x 10^-1

899.

Solve for x, If $\frac{\frac{2}{x}}{\frac{1}{p^2} + \frac{1}{p^2}}$ = m

$\frac{4pq}{m(p + q)}$

$\frac{2p^2q^2}{m(q^2 + p^2)}$

$\frac{2pq}{m(q^2 + p^2)}$

$\frac{2p^2q^2}{m(p^2)}$

View answer & explanation

Correct answer is B

$\frac{1}{p^2}$ + $\frac{1}{q^2}$ = $\frac{q^2 + p^2}{p^2 + q^2}$

$\frac{\frac{2}{x}}{\frac{p^2 + q^2}{p^2 q^2}}$

m = $\frac{2p^2q^2}{x(p^2 + q^2)}$

= m2p2q2 = m x (p2 + q2)

x = $\frac{2p^2q^2}{m(q^2 + p^2)}$