WAEC Mathematics Past Questions & Answers - Page 337

1,681.

Simplify 0.63954 ÷ 0.003 giving your answer correct to two significant figures

A.

213.18

B.

213.00

C.

213

D.

210

E.

21

Correct answer is D

= \(\frac{0.63954}{0.003}\) 

moving the decimal places, we have

= \(\frac{639.54}{3}\)

= 213.18

\(\approxeq\) 210 (to 2 s.f.)

1,682.

Cos x is negative and sin x is negative.Which of the following is true of x?

A.

0o < x < 90o

B.

90o < x <180o

C.

180o < x < 270o

D.

270o < x <360o

E.

-90o < x <90o

Correct answer is C

In the 3rd quadrant, only the tan of angles are positive.

The 3rd quadrant = 180° < x < 270°

1,683.

If log\(_{10}\) q = 2.7078, what is q?

A.

5102

B.

849.9

C.

510.2

D.

84.99

E.

51.02

Correct answer is C

q = 10\(^{2.7078}\)

Antilog of 2.7078 = 510.2

1,684.

What value of k makes the given expression a perfect square ? m\(^2\) - 8m + k = 0

A.

2

B.

4

C.

8

D.

16

E.

64

Correct answer is D

Take half the coefficient of m and square it
=> (-8/2)2 = k = 16

1,685.

Find the root of the equation 2x\(^2\) - 3x - 2 = 0

A.

x = -2 or 1/2

B.

x = -2 or1

C.

x = -2 or 2

D.

x = -1 or 2

E.

x = -1/2 or 2

Correct answer is E

2x\(^2\) - 3x - 2 = 0

2x\(^2\) - 4x + x - 2 = 0

2x(x - 2) + 1(x - 2) = 0

(2x + 1)(x - 2) = 0

x = \(\frac{-1}{2}\) or x = 2