Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Continuity and Differentiability

Question:

If x + 2|y| = 3y, where y = f(x), then f(x) is

Options:

continuous everywhere

differentiable everywhere

discontinuous at x = 0

none of the above

Correct Answer:

continuous everywhere

Explanation:

$\left.\begin{matrix}x+2y=3y&(y≥0)\\x-2y=3y&(y<0)\end{matrix}\right\}⇒y=\left\{\begin{matrix}x&(x≥0)\\\frac{x}{5}&(x<0)\end{matrix}\right.$

function is continuous everywhere, but not differentiable at x = 0.