Waec Further Mathematics 2012 Past Questions and Answers

Question 21:

• WAEC 2012

Differentiate \(\frac{x}{x + 1}\) with respect to x.

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

Question 22:

• WAEC 2012

Two forces 10N and 6N act in the directions 060° and 330° respectively. Find the x- component of their resultant.

A. \(5\sqrt{3} - 3\)
B. \(3 - 5\sqrt{3}\)
C. \(5 - 3\sqrt{3}\)
D. \(3\sqrt{3} - 5\)

Question 23:

• WAEC 2012

Find the unit vector in the direction of the vector \(-12i + 5j\).

A. \(\frac{-12i}{13} - \frac{5j}{13}\)
B. \(\frac{-1i}{13} + \frac{5j}{13}\)
C. \(\frac{-12i}{13} + \frac{5j}{13}\)
D. \(\frac{-5i}{13} + \frac{12j}{13}\)

Question 24:

• WAEC 2012

In computing the mean of 8 numbers, a boy mistakenly used 17 instead of 25 as one of the numbers and obtained 20 as the mean. Find the correct mean

A. 19
B. 21
C. 23
D. 24

Question 25:

• WAEC 2012

Given that \(^{n}P_{r} = 90\) and \(^{n}C_{r} = 15\), find the value of r.

A. 2
B. 3
C. 5
D. 6