ExamBro
ExamBro
CUET · MATHS · PYQ PAPER 2025

If the function
\(f(x)=\left\{\begin{array}{ll}a x+2, & x \leq 1 \\x^2+3 x+b, & x>1\end{array}\right.\)
is differentiable at \(x=1\), then the value of \((2 a+b)\) is

  1. A 13
  2. B 11
  3. C 16
  4. D 8
Verified Solution

Answer & Solution

Correct Answer

(A) 13

Step-by-step Solution

Detailed explanation

Continuity at \(x=1\): \(a(1)+2 = (1)^2+3(1)+b \implies a+2 = 4+b \implies a-b=2\) Differentiability at \(x=1\): \(f'\_(1) = f'\_+(1)\) \(a = 2(1)+3 \implies a=5\) \(5-b=2 \implies b=3\) \(2a+b = 2(5)+3 = 10+3=13\)
From CUET
Explore more questions on app