Target Exam

CUET

Subject

-- Mathematics - Section A

Chapter

Applications of Derivatives

Question:

What is the minimum value of  y = \(\frac{ { x }^{ 2 } }{2}-3x\)?

Options:

$9/2$

$-9/2$

$9/4$

$-9/4$

Correct Answer:

$-9/2$

Explanation:

The correct answer is Option (2) → $-9/2$

$f(x)=\frac{x^2}{2}-3x$

for extreme values, $f'(c)=0$

$⇒2x-3=0$

$⇒x=3/2$

$∴f(\frac{3}{2})=\frac{9}{8}-\frac{9}{2}$

$=-\frac{9}{2}$