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.

276.

Two functions f and g are defined on the set R of real numbers by \(f : x \to 2x - 1\) and \(g : x \to x^{2} + 1\). Find the value of \(f^{-1} \circ g(3)\).

A.

12

B.

11

C.

\(\frac{11}{2}\)

D.

\(\frac{9}{2}\)

Correct answer is C

\(f(x) = 2x - 1; g(x) = x^{2} + 1\)

\(f(x) = 2x - 1\)

\(f(y) = 2y - 1 \)

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

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

\(g(3) = 3^{2} + 1 = 10\)

\(f^{-1}(10) = \frac{10 + 1}{2} = \frac{11}{2}\)

277.

The sum of the first three terms of an Arithmetic Progression (A.P) is 18. If the first term is 4, find their product

A.

130

B.

192

C.

210

D.

260

Correct answer is B

\(S_{n} = \frac{n}{2}(2a + (n - 1)d)\) ( for an arithmetic progression)

\(S_{3} = 18 = \frac{3}{2}(2(4) + (3 - 1) d) \)

\(18 = \frac{3}{2} (8 + 2d)\)

\(18 = 12 + 3d \implies 3d = 6\)

\(d = 2\)

\(\therefore T_{1} = 4 \implies T_{2} = 4 + 2 = 6; T_{3} = 6 + 2 = 8\)

Their product = \(4 \times 6 \times 8 = 192\)

278.

Which of the following is the same as \(\sin (270 + x)°\)?

A.

\(\sin x\)

B.

\(\tan x\)

C.

\(- \sin x \)

D.

\(- \cos x\)

Correct answer is D

No explanation has been provided for this answer.

279.

Given that \(\alpha\) and \(\beta\) are the roots of an equation such that \(\alpha + \beta = 3\) and \(\alpha \beta = 2\), find the equation.

A.

\(x^{2} - 3x + 2 = 0\)

B.

\(x^{2} - 2x + 3 = 0\)

C.

\(x^{2} - 3x - 2 = 0\)

D.

\(x^{2} - 2x - 3 = 0\)

Correct answer is A

Given \(ax^{2} + bx + c = 0 (\text{general form of a quadratic equation})\)

We have \(x^{2} + \frac{b}{a}x + \frac{c}{a} = 0\)

\( x^{2} - (-\frac{b}{a})x + \frac{c}{a} = 0\)

\(\implies x^{2} - (\alpha + \beta)x + (\alpha \beta) = 0\)

\(\therefore \text{The equation is} x^{2} - 3x + 2 = 0\) 

280.

Given that the straight lines \(kx - 5y + 6 = 0\) and \(mx + ny - 1 = 0\) are parallel, find a relationship connecting the constants m, n and k.

A.

5n - km = 0

B.

kn + 5m = 0

C.

5n + km = 0

D.

kn - 5m = 0

Correct answer is B

Two lines are parallel if and only if their slopes are equal.

\(kx - 5y + 6 = 0 \implies 5y = kx + 6\)

\(y = \frac{k}{5}x + \frac{6}{5}\)

\(Slope = \frac{k}{5}\)

\(mx + ny - 1 = 0 \implies ny = 1 - mx\)

\(y = \frac{1}{n} - \frac{m}{n}x\)

\(Slope = -\frac{m}{n}\)

\(Parallel \implies \frac{k}{5} = -\frac{m}{n}\)

\(-5m = kn \implies 5m + kn = 0\)