WAEC Past Questions and Answers - Page 1040

5,196.

In what interval is the function f : x -> 2x - x\(^2\) increasing? 

A.

x = 1

B.

x < 1

C.

x > 1

D.

0 < x < 1

Correct answer is C

2x - x\(^2\) > 0

0 > x\(^2\) - 2x

x\(^2\) - 2x < 0

x(x - 2) < 0 

x > 1

5,197.

A function f defined by f : x -> x\(^2\) + px + q is such that f(3) = 6 and f(3) = 0. Find the value of q.

A.

-9

B.

-6

C.

15

D.

21

Correct answer is C

f(x) = x\(^3\) + px + q

f(3) 3\(^2\) + 3pf + q = 6

f\(^{1}\)(x) = 2x + p

f\(^1\)(3) = 2(3) + p = 0

p = -6

from 9 + 3p + q = 6

9 + 3(-6) + q = 6

9 - 18 + q = 6

-9 + q = 6

Q = 6 + 9

= 15 

5,198.

Which of the following is not an equation of a circle?

A.

3x\(^2\) +3y\(^2\) + 5x + 7y =5

B.

x\(^2\) + y\(^2\) + 5x + 4y = 0

C.

5x\(^2\) + 5y\(^2\) - 16 = 0

D.

x\(^2\) - y\(^2\) + 3x - 5y = 2

Correct answer is D

No explanation has been provided for this answer.

5,199.

In how many ways can the letters of the word MEMBER be arranged?

A.

720

B.

360

C.

180

D.

90

Correct answer is C

No. of ways = \(\frac{6!}{2!2!}\)

= \(\frac{6 \times 5 \times 4 \times 3 \times 2!}{2 \times 1 \times 2!}\)

= 180 ways

5,200.

Calculate, correct to two decimal places, the area enclosed by the line 3x - 5y + 4 = 0 and the axes.

A.

0.50 square units

B.

0.51 square units

C.

0.53 square units

D.

0.54 square units

Correct answer is C

Area = \(\frac{1}{2} \times 1.33 \times 0.8\)

= 0.53 square unit