JAMB Mathematics Past Questions & Answers - Page 422

2,106.

Find the value of x for which the function y = x3 - x has a minimum value.

A.

\(-\sqrt{3}\)

B.

\(-\sqrt{\frac{3}{3}}\)

C.

\(\sqrt{\frac{3}{3}}\)

D.

\(\sqrt{3}\)

Correct answer is C

No explanation has been provided for this answer.

2,107.

Evaluate \(\int^{1}_{-2}(x-1)^{2}dx\)

A.

\(\frac{-10}{3}\)

B.

7

C.

9

D.

11

Correct answer is C

No explanation has been provided for this answer.

2,108.

What is the derivative of t2 sin (3t - 5) with respect to t?

A.

6t cos (3t - 5)

B.

2t sin (3t - 5) - 3t2 cos (3t - 5)

C.

2t sin (3t - 5) + 3t2 cos (3t - 5)

D.

2t sin (3t - 5) + t2 cos 3t

Correct answer is C

t2 sin (3t - 5) = 2t sin ( 3t - 5) + t2 x 3 cos (3t - 5) = 2t sin (3t - 5) + 3t2 cos (3t - 5)

2,109.

Find the volume of solid generated when the area enclosed by y = 0, y = 2x, and x = 3 is rotated about the x-axis.

A.

81 π cubic units

B.

36 π cubic units

C.

18 π cubic units

D.

9 π cubic units

Correct answer is B

\(y = 2x \\ V = \int\pi^{2}dy \\ but\hspace{1mm}y = 2x \\ V = \int\pi4x^{2}dx\\ V = \frac{4(3)^{3}\pi}{3}-\frac{4(3)^{3}\pi}{3}\\V=\frac{4*27\pi}{3} = 36\pi \hspace{1mm}cubic\hspace{1mm}units\)

2,110.

Evaluate: \(\int^{z}_{0}(sin x - cos x) dx \hspace{1mm}Where\hspace{1mm}letter\hspace{1mm}z = \frac{\pi}{4}. (\pi = pi)\)

A.

\(\sqrt{2 +1}\)

B.

\(\sqrt{2 }-1\)

C.

\(-\sqrt{2 }-1\)

D.

\(1-\sqrt{2}\)

Correct answer is B

No explanation has been provided for this answer.