1992 - JAMB Mathematics Past Questions and Answers - page 5

(\begin{array}{c|c} & & 1 & 2 & 3 & 4 & 5 & 6 \ \hline a & 1 & 1, 1 & 1, 2 & 1, 3 & 1, 4 & 1, 5 & 1, 6\hline & 2 & 1,1 & 2, 2 & 2, 3 & 2, 4 & 2, 5 & 2, 6 \hline B & 3 & 3, 1 & 3, 2 & 3, 3 & 3, 4 & 3, 5 & 3, 6\hline & 4 & 4 , 1 & 4, 2 & 4, 3 & 4, 4 & 4, 5 & 4, 6\hline Die & 5 & 5, 1 & 5, 2 & 5, 3 & 5, 4 & 5, 5 & 5, 6 \hline & 6 & 6, 1 & 6, 2 & 6, 3 & 6, 4 & 6, 5 & 6, 6\end{array})

Probability of obtaining total score of 8 = (\frac{5}{36})

Given the graph and the curve y = ax² + bx + c the roots are x - 2 and 2 while its equation (x + 2)(x - 2) = y

y = x² - 4 i.e. y = x² + 0x - 4

a = 1, b = 0 and c = -4

Area of the quadrant = (\frac{1}{4} \pi r^2 = \frac{1}{4} \pi (6)^2)

= (\frac{36 \pi}{4} = 9 \pi )

Area of the triangle = (\frac{1}{2} \times 6 = 18 \times \sin 90^o = 18)

Area of shaded portion =(9 (\pi ) - 18)cm^2) =

9((\pi - 2)cm^2).