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.

486.

If \(g(x) = \frac{x + 1}{x - 2}, x \neq -2\), find \(g^{-1}(2)\).

A.

3

B.

2

C.

\(\frac{3}{4}\)

D.

-3

Correct answer is D

\(g(x) = \frac{x + 1}{x + 2}, x \neq 2\)

Let y = x, then \(g(y) = \frac{y + 1}{y + 2}\)

Let x = g(y), so that \(x = \frac{y + 1}{y + 2}\)

\(x(y + 2) = y + 1\)

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

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

\(y = g^{-1}(x) = \frac{1 - 2x}{x - 1}\)

\(g^{-1}(2) = \frac{1 - 2(2)}{2 - 1} = -3\)

487.

P and Q are the points (3, 1) and (7, 4) respectively. Find the unit vector along PQ.

A.

\(\begin{pmatrix} 4 \\ 3 \end{pmatrix}\)

B.

\(\begin{pmatrix} 0.6 \\ 0.8 \end{pmatrix}\)

C.

\(\begin{pmatrix} 0.8 \\ 0.6 \end{pmatrix}\)

D.

\(\begin{pmatrix} -0.8 \\ 0.6 \end{pmatrix}\)

Correct answer is C

\(PQ = \begin{pmatrix} 7 - 3 \\ 4 - 1 \end{pmatrix}\)

\(= \begin{pmatrix} 4 \\ 3 \end{pmatrix}\)

\(\hat{n} = \frac{\overrightarrow{PQ}}{|PQ|} \)

\(|PQ| = \sqrt{4^{2} + 3^{2}} = \sqrt{25} = 5\)

\(\hat{n} = \frac{1}{5}\begin{pmatrix} 4 \\ 3 \end{pmatrix} = \begin{pmatrix} 0.8 \\ 0.6 \end{pmatrix}\) 

488.

Two out of ten tickets on sale for a raffle draw are winning tickets. If a guest bought two tickets, what is the probability that both tickets are winning tickets?

A.

\(\frac{1}{80}\)

B.

\(\frac{1}{45}\)

C.

\(\frac{1}{20}\)

D.

\(\frac{1}{10}\)

Correct answer is B

P(winning) = \(\frac{2}{10}\)

P(both tickets winning) = \(\frac{2}{10} \times \frac{1}{9} = \frac{1}{45}\)

489.

Given that \(P = \begin{pmatrix} 3 & 4 \\ 2 & x \end{pmatrix}; Q = \begin{pmatrix} 1 & 3 \\ -2 & 4 \end{pmatrix}; R = \begin{pmatrix} -5 & 25 \\ -8 & 26 \end{pmatrix}\)  and PQ = R, find the value of x.

A.

-5

B.

-2

C.

2

D.

5

Correct answer is D

\(P = \begin{pmatrix} 3 & 4 \\ 2 & x \end{pmatrix}; Q = \begin{pmatrix} 1 & 3 \\ -2 & 4 \end{pmatrix}; R = \begin{pmatrix} -5 & 25 \\ -8 & 26 \end{pmatrix}\) 

PQ = \(\begin{pmatrix} 3 & 4 \\ 2 & x \end{pmatrix} \begin{pmatrix} 1 & 3 \\ -2 & 4 \end{pmatrix} = \begin{pmatrix} -5 & 25 \\ 2 - 2x & 6 + 4x \end{pmatrix} = R\)

\(\implies 2 - 2x = -8; -2x = -8 - 2 = -10\)

\(6 + 4x = 26 \implies 4x = 26 - 6 = 20\)

\(\implies x = 5\)

490.

Find the upper quartile of the following scores: 41, 29, 17, 2, 12, 33, 45, 18, 43 and 5.

A.

45

B.

41

C.

33

D.

21

Correct answer is B

Arranging the scores in ascending order, we have: 2, 5, 12, 17, 21, 29, 33, 41, 43, 45.

The upper quartile = 41.