ExamBro
ExamBro
KCET · Maths · Application of Derivatives

The value of \(C\) in \((0,2)\) satisfying the mean value theorem for the function
\(f(x)=x(x-1)^2, x \in[0,2]\) is equal to

  1. A \(3 / 4\)
  2. B \(4 / 3\)
  3. C \(1 / 3\)
  4. D \(2 / 3\)
Verified Solution

Answer & Solution

Correct Answer

(B) \(4 / 3\)

Step-by-step Solution

Detailed explanation

\(f(x)=x(x-1)^2 ; x \in[0,2]\)
\(f^{\prime}(c)=\frac{f(b)-f(a)}{b-a} ; f(2)=2, f(0)=0\)
\(\therefore f^{\prime}(x)=(x-1)^2+2 x(x-1)\)
\(=x^2+1-2 x+2 x^2-2 x\)
\(=3 x^2-4 x+1\)
So, \(f^{\prime}(c)=3 c^2-4 c+1\)
Thus, \(3 c^2-4 c+1=\frac{f(2)-(0)}{2-0}=\frac{2-0}{2-0}=1\)
\(\Rightarrow \quad c(3 c-4)=0\)
Hence, \(c=\frac{4}{3}\)