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WAEC Mathematics Past Questions & Answers - Page 335

1,671.

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°

1,672.

If log10 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 = 102.7078

Antilog of 2.7078 = 510.2

1,673.

What value of k makes the given expression a perfect square ? m2 - 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

1,674.

Find the root of the equation 2x2 - 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

2x2 - 3x - 2 = 0

2x2 - 4x + x - 2 = 0

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

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

x = 12 or x = 2

1,675.

Evaluate log106 + log1045 - log1027 without using logarithm tables

A.

0

B.

1

C.

1.1738

D.

1.3802

E.

10

Correct answer is B

log106 + log1045 - log1027

log10 6×4527

= log102 x 5

log1010 = 1