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.

351.

Given that \(2^{x} = 0.125\), find the value of x.

A.

0

B.

-1

C.

-2

D.

-3

Correct answer is D

\(2^{x} = 0.125 = \frac{125}{1000}\)

\(2^{x} = \frac{1}{8} = 8^{-1}\)

\(2^{x} = 2^{-3}\)

\(x = -3\)

352.

The roots of the quadratic equation \(2x^{2} - 5x + m = 0\) are \(\alpha\) and \(\beta\), where m is a constant. Find \(\alpha^{2} + \beta^{2}\) in terms of m

A.

\(\frac{25}{4} - m\)

B.

\(\frac{25}{4} - 2m\)

C.

\(\frac{25}{4} + m\)

D.

\(\frac{25}{4} + 2m\)

Correct answer is A

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

\(a = 2, b = -5, c = m\)

\(\alpha + \beta = \frac{-b}{a} = \frac{5}{2}\)

\(\alpha \beta = \frac{c}{a} = \frac{m}{2}\)

\(\alpha^{2} + \beta^{2} = (\alpha + \beta)^{2} - 2\alpha\beta\)

= \((\frac{5}{2})^{2} - 2(\frac{m}{2}) \)

= \(\frac{25}{4} - m\)

353.

Express \(\frac{2}{3 - \sqrt{7}} \text{ in the form} a + \sqrt{b}\), where a and b are integers.

A.

\(6 + \sqrt{7}\)

B.

\(3 + \sqrt{7}\)

C.

\(3 - \sqrt{7}\)

D.

\(6 - \sqrt{7}\)

Correct answer is B

Rationalizing \(\frac{2}{3 - \sqrt{7}}\) by multiplying through with \(3 + \sqrt{7}\),

\(\frac{2}{3 - \sqrt{7}} \frac{(3 + \sqrt{7})}{(3 + \sqrt{7})} = \frac{6 + 2\sqrt{7}}{9 - 7}\)

= \(\frac{6 + 2\sqrt{7}}{2} = 3 + \sqrt{7}\)

354.

Which of the following binary operations is not commutative?

A.

\(a * b = \frac{1}{a} + \frac{1}{b}\)

B.

\(a * b = a + b - ab\)

C.

\(a * b = 2a + 2b + ab\)

D.

\(a * b = a - b + ab\)

Correct answer is D

All other options given are commutative i.e. \(a * b = b * a\), except option D.

\(a * b = a - b + ab\)

\(b * a = b - a + ba\)

\(a - b = -(b - a) \neq b - a\)

355.

Find the coefficient of \(x^{4}\) in the binomial expansion of \((2 + x)^{6}\)

A.

120

B.

80

C.

60

D.

15

Correct answer is C

\((2 + x)^{6} \)

\(x^{4} = ^{6}C_{2}(2^{2})(x^{4}) = 15 \times 4 = 60\)