WAEC Further Mathematics Past Questions & Answers - Page 48

236.

If \((x - 3)\) is a factor of \(2x^{3} + 3x^{2} - 17x - 30\), find the remaining factors.

A.

(2x - 5)(x - 2)

B.

(2x - 5)(x + 2)

C.

(2x + 5)(x - 2)

D.

(2x + 5)(x + 2)

Correct answer is D

Divide \(2x^{3} + 3x^{2} - 17x - 30\) by \((x - 3)\). You get \(2x^{2} + 9x + 10\).

Factorizing, we have \(2x^{2} + 9x + 10 = 2x^{2} + 4x + 5x + 10\)

\(2x(x + 2) + 5(x + 2)\)

= \((2x + 5)(x + 2)\)

237.

A binary operation ♦ is defined on the set R, of real numbers by \(a ♦ b = \frac{ab}{4}\). Find the value of \(\sqrt{2} ♦ \sqrt{6}\)

A.

\(\sqrt{3}\)

B.

\(\frac{3\sqrt{2}}{4}\)

C.

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

D.

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

Correct answer is C

\(a ♦ b = \frac{ab}{4}\)

\(\sqrt{2} ♦ \sqrt{6} = \frac{\sqrt{2} \times \sqrt{6}}{4} = \frac{\sqrt{12}}{4}\)

= \(\frac{2\sqrt{3}}{4} \)

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

238.

Simplify \(\sqrt{(\frac{-1}{64})^{\frac{-2}{3}}}\)

A.

-4

B.

\(-\frac{1}{4}\)

C.

\(\frac{1}{8}\)

D.

4

Correct answer is D

\((\frac{-1}{64})^{\frac{-2}{3}} = -64^{\frac{2}{3}}\)

\((-4^{3})^{\frac{2}{3}} = -4^{2} = 16\)

\(\therefore \sqrt{(\frac{-1}{64})^{\frac{-2}{3}} = \sqrt{16} = 4\)

239.

Solve the inequality \(2x^{2} + 5x - 3 \geq 0\).

A.

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

B.

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

C.

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

D.

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

Correct answer is A

No explanation has been provided for this answer.

240.

\(P = {x : 1 \leq x \leq 6}\) and \(Q = {x : 2 < x < 9}\) where \(x \in R\), find \(P \cap Q\).

A.

\({x : 2 \leq x \leq 6}\)

B.

\({x : 2 \leq x < 6}\)

C.

\({x : 2 < x < 6}\)

D.

\({x : 2 < x \leq 6}\)

Correct answer is D

No explanation has been provided for this answer.