Waec Mathematics Past Questions For Year 1999
Question 16
If \(tan x = \frac{1}{\sqrt{3}}\), find cos x - sin x such that \(0^o \leq x \leq 90^o\)
- A. \(\frac{\sqrt{3}+1}{2}\)
- B. \(\frac{2}{\sqrt{3}+1}\)
- C. \(\frac{\sqrt{3}-1}{2}\)
- D. \(\frac{2}{\sqrt{3}-1}\)
Question 17
If y varies inversely as x\(^2\), how does x vary with y?
- A. x varies inversely as y2
- B. x varies inversely as √y
- C. x varies directly as y2
- D. x varies directly as y
Question 18
Simplify \(\frac{4}{x+1}-\frac{3}{x-1}\)
- A. \(\frac{x+7}{x^2 - 1}\)
- B. \(\frac{x-7}{x^2 + 1}\)
- C. \(\frac{x-7}{x^2 - 1}\)
- D. \(\frac{x-11}{x^2 - 1}\)
Question 19
Given that \(81\times 2^{2n-2} = K, find \sqrt{K}\)
- A. \(4.5\times 2^{n}\)
- B. \(4.5\times 2^{2n}\)
- C. \(9\times 2^{n-1}\)
- D. \(9\times 2^{2n}\)
Question 20
If \(y = \sqrt{ax-b}\) express x in terms of y, a and b
- A. \(x = \frac{y^2-b}{a}\)
- B. \(x = \frac{y+b}{a}\)
- C. \(x = \frac{y-b}{a}\)
- D. \(x = \frac{y^2 + b}{a}\)
