Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Continuity and Differentiability

Question:

Match List-I with List-II

List-I

List-II

(A) $f(x) = |x|$

(I) Not differentiable at $x=-2$ only

(B) $f(x) = |x+2|$

(II) Not differentiable at $x = 0$ only

(C) $f(x) = |x^2-4|$

(III) Not differentiable at $x = 2$ only

(D) $f(x)=|x-2|$

(IV) Not differentiable at $x = 2,-2$ only

Choose the correct answer from the options given below:

Options:

(A)-(I), (B)-(II), (C)-(III), (D)-(IV)

(A)-(II), (B)-(I), (C)-(IV), (D)-(III)

(A)-(II), (B)-(I), (C)-(III), (D)-(IV)

(A)-(IV), (B)-(III), (C)-(II), (D)-(I)

Correct Answer:

(A)-(II), (B)-(I), (C)-(IV), (D)-(III)

Explanation:

The correct answer is Option (2) → (A)-(II), (B)-(I), (C)-(IV), (D)-(III)

List-I

List-II

(A) $f(x) = |x|$

(II) Not differentiable at $x = 0$ only

(B) $f(x) = |x+2|$

(I) Not differentiable at $x=-2$ only

(C) $f(x) = |x^2-4|$

(IV) Not differentiable at $x = 2,-2$ only

(D) $f(x)=|x-2|$

(III) Not differentiable at $x = 2$ only

$(A)\ f(x)=|x|$

$|x|=\begin{cases}x,&x\ge 0\\-x,&x<0\end{cases}$

Left derivative at $x=0=-1$, right derivative at $x=0=1$

$f'(0^-)\ne f'(0^+)$

Not differentiable at $x=0$ only

$(A)\rightarrow(II)$

$(B)\ f(x)=|x+2|$

Corner point when $x+2=0$

$x=-2$

Not differentiable at $x=-2$ only

$(B)\rightarrow(I)$

$(C)\ f(x)=|x^2-4|$

$x^2-4=0 \Rightarrow x=\pm2$

Sign of $x^2-4$ changes at $x=2,-2$

Derivative is discontinuous at both points

Not differentiable at $x=2,-2$

$(C)\rightarrow(IV)$

$(D)\ f(x)=|x-2|$

Corner point when $x-2=0$

$x=2$

Not differentiable at $x=2$ only

$(D)\rightarrow(III)$

Final Matching: (A)-(II), (B)-(I), (C)-(IV), (D)-(III).