ExamBro
ExamBro
AP EAMCET · Maths · Continuity and Differentiability

If \(f(x)=\left\{\begin{array}{cc}2 x+3, & x \leq 1 \\ a x^2+b x, & x\gt1\end{array}\right.\) is differentiable \(\forall x \in \mathbb{R}\), then \(f(2)=\)

  1. A 5
  2. B 4
  3. C -4
  4. D -10
Verified Solution

Answer & Solution

Correct Answer

(C) -4

Step-by-step Solution

Detailed explanation

\(f(x)=\left\{\begin{array}{cc}2 x+3, & x \leq 1 \\ a x^2+b x & , x\gt1\end{array}\right.\) \(f(x)\) is differentiable \(\forall x \in \mathbf{R}\) \(\Rightarrow \lim _{x \rightarrow 1^{-}} f^{\prime}(x)=\lim _{x \rightarrow 1^{+}} f^{\prime}(x) \Rightarrow 2=2 a+b\)…