1990 - WAEC Mathematics Past Questions and Answers - page 2
Find the values of x for which y = 5
An arc of length 22cm subtends an angle of θ at the center of the circle. What is the value of θ if the radius of the circle is 15cm?[Take π = 22/7]
\(2\pi r = 2 \times 3.142 \times 15 = 94.28cm\)
\(94.28cm = 360°\)
\(1cm = \frac{360°}{94.28}\)
\(\therefore 22cm = \frac{360°}{94.28} \times 22\)
= 84°
Users' Answers & CommentsFind the sum of the first five terms of the G.P 2,6, 18 ....
\(S_{n} = \frac{a(r^n - 1)}{r - 1}\)
a = 2; r = 6/2 = 3.
\(S_{5} = \frac{2(3^5 - 1)}{3 - 1}\)
= \(243 - 1 = 242\)
Users' Answers & CommentsLet J be the set of positive integers, If H = {x: x∈J, x\(^2\) < 3 and x ≠ 0}, then
H = {x: x is a positive integer, x\(^2\) < 3 and x \(\neq\) 0}
H = {1}
Users' Answers & Comments∩(E∩G) = ∩(E) + ∩(G) - ∩(E∩G)
80 = 65 + 50 - ∩(F∩G)
∴∩(E∩G) = 115 - 80 = 35
In the diagram above, O is the center of the circle with radius 10cm, and ∠ABC = 30°. Calculate, correct to 1 decimal place, the length of arc AC [Take π = 22/7]
In the figure, < AOC = 2 x < ABC = 60° (angle subtended at the centre)
\(\therefore\) Arc AC = \(\frac{60}{360} \times 2 \times 10 \times 3.14\)
= \(\frac{31.4}{3}\)
= 10.466 cm \(\approxeq\) 10.5 cm
Users' Answers & CommentsFactorize x\(^2\) + 4x - 192
x\(^2\) + 4x - 192
x\(^2\) + 16x - 12x - 192
x(x + 16) - 12(x + 16)
(x + 16)(x - 12)
Users' Answers & CommentsFactorize 2e\(^2\) - 3e + 1
2e\(^2\) - 3e + 1
2e\(^2\) - 2e - e + 1
2e(e - 1) - 1(e - 1)
(2e - 1)(e - 1)
Users' Answers & Comments