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.

506.

Given that \(P = \begin{pmatrix} y - 2 & y - 1 \\ y - 4 & y + 2 \end{pmatrix}\) and |P| = -23, find the value of y.

A.

-4

B.

-3

C.

-1

D.

2

Correct answer is B

\(P = begin{pmatrix} y - 2 & y - 1 \\ y - 4 & y + 2 \end{pmatrix}\)

\(|P| = (y - 2)(y + 2) - (y - 1)(y - 4) = (y^{2} - 4) - (y^{2} - 5y + 4) = -23\)

\(5y - 8 = -23 \implies 5y = -23 + 8 = -15\)

\(y = \frac{-15}{5} = -3\)

507.

Given that \(\frac{\mathrm d y}{\mathrm d x} = \sqrt{x}\), find y.

A.

\(2x^{\frac{3}{2}} + c\)

B.

\(\frac{2}{3}x^{\frac{3}{2}} + c\)

C.

\(\frac{3}{2}x^{\frac{3}{2}} + c\)

D.

\(\frac{2}{3}x^{2} + c\)

Correct answer is B

\(\frac{\mathrm d y}{\mathrm d x} = \sqrt{x} = x^{\frac{1}{2}}\)

\(y = \int x^{\frac{1}{2}} \mathrm {d} x\)

= \(\frac{x^{\frac{1}{2} + 1}}{\frac{1}{2} + 1} + c = \frac{x^{\frac{3}{2}}}{\frac{3}{2}} + c \)

= \(\frac{2}{3}x^{\frac{3}{2}} + c\)

508.

Find the range of values of x for which \(x^{2} + 4x + 5\) is less than \(3x^{2} - x + 2\)

A.

\(x > \frac{-1}{2}, x > 3\)

B.

\(x < \frac{-1}{2}, x > 3\)

C.

\(\frac{-1}{2} \leq x \leq 3\)

D.

\(\frac{-1}{2} < x < 3\)

Correct answer is B

No explanation has been provided for this answer.

509.

The fourth term of an exponential sequence is 192 and its ninth term is 6. Find the common ratio of the sequence.

A.

\(\frac{1}{3}\)

B.

\(\frac{1}{2}\)

C.

\(2\)

D.

\(3\)

Correct answer is B

\(T_{n} = ar^{n - 1}\)

\(T_{4} = ar^{4 - 1} = ar^{3} = 192\)

\(T_{9} = ar^{9 - 1} = ar^{8} = 6\)

Dividing \(T_{9}\) by \(T_{4}\), 

\(r^{8 - 3} = \frac{6}{192}\)

\(r^{5} = \frac{1}{32} = (\frac{1}{2})^{5}\)

\(r = \frac{1}{2}\)

510.

Differentiate \(x^{2} + xy - 5 = 0\)

A.

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

B.

\(\frac{(2x - y)}{x}\)

C.

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

D.

\(\frac{(2x + y)}{x}\)

Correct answer is A

\(\frac{\mathrm d}{\mathrm d x}(x^2 + xy - 5) = \frac{\mathrm d (x^{2})}{\mathrm d x} + \frac{\mathrm d (xy)}{\mathrm d x} - \frac{\mathrm d (5)}{\mathrm d x} = 0\)

= \(2x + x\frac{\mathrm d y}{\mathrm d x} + y = 0\)

\(\implies x\frac{\mathrm d y}{\mathrm d x} = -(2x + y)\)

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