1998 - WAEC Mathematics Past Questions and Answers - page 1
Find the root of the equation 2x\(^2\) - 3x - 2 = 0
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
What value of k makes the given expression a perfect square ? m\(^2\) - 8m + k = 0
Take half the coefficient of m and square it
=> (-8/2)2 = k = 16
If log\(_{10}\) q = 2.7078, what is q?
Cos x is negative and sin x is negative.Which of the following is true of x?
In the 3rd quadrant, only the tan of angles are positive.
The 3rd quadrant = 180° < x < 270°
Simplify 0.63954 ÷ 0.003 giving your answer correct to two significant figures
= \(\frac{0.63954}{0.003}\)
moving the decimal places, we have
= \(\frac{639.54}{3}\)
= 213.18
\(\approxeq\) 210 (to 2 s.f.)
If log\(_{10}\) a = 4; what is a?
A student measured the length of a room and obtained the measurement of 3.99m. If the percentage error of is measurement was 5% and his own measurement was smaller than the length , what is the length of the room?
Let the actual length of the room = y m
\(\therefore \frac{y - 3.99}{y} \times 100% = 5%\)
\(100(y - 3.99) = 5y \implies 100y - 399 = 5y\)
\(100y - 5y = 399 \implies y = \frac{399}{95}\)
y = 4.2 m
When an aeroplane is 800m above the ground, its angle of elevation from a point P on the ground is 30o. How far is the plane from P by line of sight?
From the diagram, \(\sin 30 = \frac{800}{x}\)
\(x = \frac{800}{\sin 30} \)
= \(\frac{800}{0.5} \)
= 1600 m
Convert 35 to a number in base two
3 x 22 - 1 = 6
3 x 22 - 2 = 3
3 x 22 - 3 = 3/2