WAEC Further Mathematics Past Questions & Answers - Page 12

56.

If g(x) = √(1-x\(^2\)), find the domain of g(x)

A.

x < -1 or x > 1

B.

x ≤ -1 or x ≥1

C.

-1 ≤ x ≤ 1

D.

-1 < x < 1

Correct answer is C

1 - x\(^2\) ≥ 0
-x\(^2\) ≥ -1
x\(^2\) ≤ 1
√x\(^2\) ≤ 1
|x| ≤ 1
-1 ≤ x ≤ 1

58.

The table shows the distribution of the distance (in km) covered by 40 hunters while hunting.

Distance(km) 3 4 5 6 7 8
Frequency 5 4 x 9 2x 1

If a hunter is selected at random, find the probability that the hunter covered at least 6km.

A.

\(\frac{3}{5}\)

B.

\(\frac{2}{5}\)

C.

\(\frac{3}{8}\)

D.

\(\frac{9}{40}\)

Correct answer is A

5+4+x+9+2x+1 = 40
19+3x = 40
3x = 21
x = 7

Distance(km) 3 4 5 6 7 8
Frequency 5 4 7 9 14 1

The probability that the hunter covered at least 6km, means the hunter covered either 6km or 7km, or 8km.

24 hunters covered at least 6km

24
40
 =   3
5

59.

If →PQ = -2i + 5j and →RQ = -i - 7j, find →PR

A.

-3i + 12j

B.

-3i - 12j

C.

-i + 12j

D.

i - 12j

Correct answer is C

→PQ = →PR + →RQ
→PR = →PQ  -  →RQ
→PR = -2i + 5j - (-i - 7j)
→PR = -2i + 5j + i + 7j
→PR = -i + 12j.

60.

Given that P = (-4, -5) and Q = (2,3), express →PQ in the form (k,θ). where k is the magnitude and θ the bearing.

A.

(10 units, 053º)

B.

(9 units, 049º)

C.

(10 units, 037º)

D.

(9 units, 027º)

Correct answer is A

|→PQ| = √[(2-(-4))\(^2\) + (3-(-5))\(^2\)]
|→PQ| = √\(6^2 + 8^2\)
|→PQ| = √100
|→PQ| = 10units

tanθ = \(\frac{3--5}{2--4}\)

tanθ = \(\frac{4}{3}\) 

θ = \(tan^{-1}\frac{4}{3}\)

= 53º