JAMB Mathematics Past Questions & Answers - Page 339

1,691.

Find the median of 5,9,1,10,3,8,9,2,4,5,5,5,7,3 and 6

A.

6

B.

5

C.

4

D.

3

Correct answer is B

First arrange the numbers in order of magnitude; 1,2,3,3,4,5,5,5,5,6,7,8,9,9,10 Hence the median = 5

1,693.

The mean of 2 - t, 4 + t, 3 - 2t, 2 + t and t - 1 is

A.

t

B.

-t

C.

2

D.

-2

Correct answer is C

Mean x = \(\frac{\sum x}{n}\)

= [(2 - t) + (4 + t) + (3 - 2t) + (2 + t) + (t - 1)] \(\div\) 5

= [11 - 1 + 3t - 3t] \(\div\) 5

= 10 \(\div\) 5

= 2

1,694.

Evaluate \(\int (2x + 3)^{\frac{1}{2}} \delta x\)

A.

\(\frac{1}{12} (2x + 3)^6 + k\)

B.

\(\frac{1}{3} (2x + 3)^{\frac{1}{2}} + k\)

C.

\(\frac{1}{3} (2x + 3)^{\frac{3}{2}} + k\)

D.

\(\frac{1}{12} (2x + 3)^{\frac{3}{4}} + k\)

Correct answer is C

\(\int (2x + 3)^{\frac{1}{2}} \delta x\)

let u = 2x + 3, \(\frac{\delta y}{\delta x} = 2\)

\(\delta x = \frac{\delta u}{2}\)

Now \(\int (2x + 3)^{\frac{1}{2}} \delta x = \int u^{\frac{1}{2}}.{\frac{\delta x}{2}}\)

\( = \frac{1}{2} \int u^{\frac{1}{2}} \delta u\)

\( = \frac{1}{2} u^{\frac{3}{2}} \times \frac{2}{3} + k\)

\( = \frac{1}{3} u^{\frac{3}{2}} + k\)

\( = \frac{1}{3} (2x + 3)^{\frac{3}{2}} + k\)

1,695.

Evaluate \(\int \sin 2x dx\)

A.

cos 2x + k

B.

\(\frac{1}{2}\)cos 2x + k

C.

\(-\frac{1}{2}\)cos 2x + k

D.

-cos 2x + k

Correct answer is C

\(\int \sin 2x dx = \frac{1}{2} (-\cos 2x) + k\)

\(- \frac{1}{2} \cos 2x + k\)