Question 36:

• JAMB 2019

If \(\begin{vmatrix} 2 & -4 \\ x & 9 \end{vmatrix} = 58\), find the value of x.

A. 10
B. 30
C. 14
D. 28

Question 37:

• JAMB 2019

If \(y = 6x^3 + 2x^{-2} - x^{-3}\), find \(\frac{\mathrm d y}{\mathrm d x}\).

A. \(\frac{\mathrm d y}{\mathrm d x} = 15x^2 - 4x^{-2} - 3x^{-2}\)
B. \(\frac{\mathrm d y}{\mathrm d x} = 6x + 4x^{-1} - 3x^{-4}\)
C. \(\frac{\mathrm d y}{\mathrm d x} = 18x^2 - 4x^{-3} + 3x^{-4}\)
D. \(\frac{\mathrm d y}{\mathrm d x} = 12x^2 + 4x^{-1} - 3x^{-2}\)

Question 38:

• JAMB 2019

\(\frac{d}{dx} [\log (4x^3 - 2x)]\) is equal to

A. \(\frac{12x - 2}{4x^2}\)
B. \(\frac{43x^2 - 2x}{7x}\)
C. \(\frac{4x^2 - 2}{7x + 6}\)
D. \(\frac{12x^2 - 2}{4x^3 - 2x}\)

Question 39:

• JAMB 2019

If \(f(x) = 3x^3 + 4x^2 + x - 8\), what is the value of f(-2)?

A. -24
B. 30
C. -18
D. -50

Question 40:

• JAMB 2019

Solve for x in \(\frac{4x - 6}{3} \leq \frac{3 + 2x}{2}\)

A. \(x \leq 1\frac{1}{2}\)
B. \(x \leq \frac{21}{2}\)
C. \(x \geq \frac{21}{2}\)
D. \(x \geq 1\frac{1}{2}\)