Target Exam

CUET

Subject

-- Mathematics - Section A

Chapter

Applications of Derivatives

Question:

If $x$ is real, the minimum value of $x^2 - 8x + 20$ is

Options:

4

2

0

-1

Correct Answer:

4

Explanation:

The correct answer is Option (1) → 4

Given expression: $x^{2}-8x+20$

Complete the square:

$x^{2}-8x+20 = (x^{2}-8x+16)+4$

$=(x-4)^{2}+4$

Since $(x-4)^{2} \ge 0$, minimum occurs when $x=4$.

Minimum value $= 0 + 4 = 4$

The minimum value is 4.