Limits Continuity And Differentiability Question 11

Question: If the mean value theorem is $ f(b)-f(a)=(b-a)f’(c) $ . Then, for the function $ x^{2}-2x+3 $ in $ [ 1,\frac{3}{2} ] $ the value of c is

Options:

A) 6/5

B) 5/4

C) 4/3

D) 7/6

Show Answer

Answer:

Correct Answer: B

Solution:

Let $ f(x)=x^{2}-2x+3 $ .

Since, $ f’(c)=\frac{f( \frac{3}{2} )-f(1)}{\frac{3}{2}-1} $ (given)
$ \Rightarrow 2c-2=\frac{\frac{9}{4}-\frac{6}{2}+3-(1-2+3)}{\frac{3}{2}-1}\Rightarrow c=\frac{5}{4} $