Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Relations and Functions

Question:

The range of $f(x)=\sqrt{3 x^2-4 x+5}$ is

Options:

$\left.\frac{2}{3}, \infty\right)$

$\left.\frac{11}{3}, \infty\right)$

$\left[\frac{11}{3}, \infty\right]$

$\left(\frac{2}{3}, \infty\right)$

Correct Answer:

$\left.\frac{11}{3}, \infty\right)$

Explanation:

Given

$f(x)=\sqrt{3 x^2-4 x+5}=\sqrt{3\left(x-\frac{2}{3}\right)^2+\frac{11}{3}}$

clearly domain of f(x) is R. Now f(x) will be

minimum $\sqrt{\frac{11}{3}}$ when x = 2/3

Hence range is $\left.\frac{11}{3}, \infty\right)$

Hence (2) is the correct answer.