Further Mathematics questions and answers

Further Mathematics Questions and Answers

Test your knowledge of advanced level mathematics with this aptitude test. This test comprises Further Maths questions and answers from past JAMB and WAEC examinations.

316.

The sum of the first n terms of a linear sequence is \(S_{n} = n^{2} + 2n\). Find the common difference of the sequence

A.

5

B.

4

C.

3

D.

2

Correct answer is D

\(S_{n} = \frac{n}{2}(2a + (n - 1)d \)

\(\frac{n}{2}(2a + (n - 1) d = n^{2} + 2n\)

\(n(2a + (n - 1) d = 2n^{2} + 4n\)

\(2an + n^{2}d - nd = 2n^{2} + 4n\)

Comparing the equations, d = 2 (coefficient of \(n^{2}\)).

317.

A function f is defined on R, the set of real numbers, by: \(f : x \to \frac{x + 3}{x - 2}, x \neq 2\), find \(f^{-1}\).

A.

\(f^{-1} : x \to \frac{2x + 3}{x - 1}, x \neq 1\)

B.

\(f^{-1} : x \to \frac{x + 3}{x + 2}, x \neq -2\)

C.

\(f^{-1} : x \to \frac{x - 1}{2x + 3}, x \neq -\frac{3}{2}\)

D.

\(f^{-1}: x \to \frac{x - 2}{x + 3}, x \neq -3\)

Correct answer is A

\(f(x) = \frac{x + 3}{x - 2}\) 

\(f(y) = \frac{y + 3}{y - 2}\)

Let f(y) = x,

\(x = \frac{y + 3}{y - 2}\)

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

\(xy - y = 2x + 3 \implies y(x - 1) = 2x + 3\)

\(y = \frac{2x + 3}{x - 1}\)

318.

Find the range of values of x for which \(2x^{2} + 7x - 15 > 0\).

A.

\(x < -\frac{3}{2}\) or \(x > 5\)

B.

\(x < -5\) or \(x > \frac{3}{2}\)

C.

\(-\frac{3}{2} < x < 5\)

D.

\(-5 < x < \frac{3}{2}\)

Correct answer is B

\(2x^{2} + 7x - 15 > 0 \implies 2x^{2} - 3x + 10x - 15 > 0\)

\(x(2x - 3) + 5(2x - 3) > 0\)

\((x + 5)(2x - 3) > 0\)

For their product to be positive, they are either both +ve or -ve.

\(x + 5 > 0 \implies x > -5\)

\(2x - 3 > 0 \implies 2x > 3\)

\(x > \frac{3}{2}\)

Check:

\(x > -5: x = -3\)

\(2(-3)^{2} + 7(-3) - 15 = 18 - 21 - 15 = -18 < 0\) (Not satisfied)

\(\therefore x < -5\)

\(x > \frac{3}{2}: x = 2\)

\(2(2^{2}) + 7(2) - 15 = 8 + 14 - 15 = 7 > 0\) (Satisfied)

319.

Simplify \(\frac{\sqrt{3} + \sqrt{48}}{\sqrt{6}}\)

A.

\(3\sqrt{2}\)

B.

\(5\sqrt{2}\)

C.

\(\frac{5\sqrt{2}}{2}\)

D.

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

Correct answer is C

\(\frac{\sqrt{3} + \sqrt{48}}{\sqrt{6}} = \frac{\sqrt{3} + 4\sqrt{3}}{\sqrt{6}}\)

\(\frac{5\sqrt{3}}{\sqrt{6} = \frac{5\sqrt{3} \times \sqrt{6}}{\sqrt{6} \times \sqrt{6}}\)

\(\frac{5\sqrt{18}{6} = \frac{15\sqrt{2}}{6}\)

= \(\frac{5\sqrt{2}}{2}\)

320.

In the diagram, a ladder PS leaning against a vertical wall PR makes angle x° with the horizontal floor. The ladder slides down to a point QT such that angle QTR = 30° and SNT = y°. Find an expression for tan y.

A.

\(\frac{\sqrt{3} \tan x - 1}{\sqrt{3} + \tan x}\)

B.

\(\frac{\sqrt{3} \tan x}{\sqrt{3} + \tan x}\)

C.

\(\frac{\sqrt{3} \tan x + 1}{\sqrt{3} - \tan x}\)

D.

\(\frac{3 \tan x - 1}{\sqrt{3} - \tan x}\)

Correct answer is A

No explanation has been provided for this answer.