Verify Rolle’s theorem for each of the following functions:
Condition (1):
Since, f(x)=(x-2)4(x-3)3 is a polynomial and we know every polynomial function is continuous for all xϵR.
⇒ f(x)= (x-2)4(x-3)3 is continuous on [2,3].
Condition (2):
Here, f’(x)= 4(x-2)3(x-3)3+3(x-2)4(x-3)2 which exist in [2,3].
So, f(x)= (x-2)4(x-3)3 is differentiable on (2,3).
Condition (3):
Here, f(2)= (2-2)4(2-3)3=0
And f(3)= (3-2)4(3-3)3=0
i.e. f(2)=f(3)
Conditions of Rolle’s theorem are satisfied.
Hence, there exist at least one cϵ(2,3) such that f’(c)=0
i.e. 4(c-2)3(c-3)3+3(c-2)4(c-3)2=0
(c-2)3(c-3)2(7c-18)=0
i.e. c=2 or c=3 or c=18÷7
Value of
Thus, Rolle’s theorem is satisfied.