Question 91:

• WAEC 2016

The radius of a circle increases at a rate of 0.5\(cms^{-1}\). Find the rate of change in the area of the circle with radius 7cm. \([\pi = \frac{22}{7}]\)

A. 11\(cm^{2}s^{-1}\)
B. 22\(cm^{2}s^{-1}\)
C. 33\(cm^{2}s^{-1}\)
D. 44\(cm^{2}s^{-1}\)

Question 92:

• WAEC 2016

Find an expression for y given that \(\frac{\mathrm d y}{\mathrm d x} = x^{2}\sqrt{x}\)

A. \(\frac{1x^{\frac{2}{7}}}{7} + c\)
B. \(\frac{2x^{\frac{3}{2}}}{7} + c\)
C. \(\frac{2x^{\frac{7}{2}}}{7} + c\)
D. \(\frac{1x^{\frac{7}{2}}}{7} + c\)

Question 93:

• WAEC 2016

Evaluate \(\cos leaving the answer in surd form.

A. \(\frac{\sqrt{2}}{2}(\sqrt{3} + 1)\)
B. \(\frac{\sqrt{2}}{4}(\sqrt{3} - 1)\)
C. \(\frac{\sqrt{2}}{4}(\sqrt{3} + 1)\)
D. \(\frac{\sqrt{2}}{2}(\sqrt{3} - 1)\)

Question 94:

• WAEC 2016

Given that \(\tan x = \frac{5}{12}\), and \(\tan y = \frac{3}{4}\), Find \(\tan (x + y)\).

A. \(\frac{16}{33}\)
B. \(\frac{33}{56}\)
C. \(\frac{33}{16}\)
D. \(\frac{56}{33}\)

Question 95:

• WAEC 2016

Find the equation of the line which passes through (-4, 3) and parallel to line y = 2x + 5.

A. Y = 2x + 11
B. Y = 3x + 11
C. Y = 3x - 5
D. Y = 2x - 11