Maths for Engineers - 1

Problems On Fundamental Theorem

Problems on Fundamental Theorem:


1. Verify Rolle's Theorem for the functions f (x) = x2 - 4x 8 in the intervals [1,3].

Solutions: f (x) = x2 - 4x 8 is continuous in [1,3] and f' (x) = 2x - 4 exists for all value in (1,3)

         

 

Hence all three conditions of the theorem are satiesfied.

Now consider f ' (c) = 0

i.e                 2c - 4 = 0 ⇒ 2c = 4.

                

and hence Rolle's Theorem is varified.

2. Varify Rolle's Theorem for the functions

Solutions:

          

Therefore f' (x) exists for all x. Also,

             

             

Hence all the three conditions of the theorem are satiesfied.

Now consider f' (c) = 0

Hence three exists - 2 ∈ ( -3,0) such that

            f' (-2) = 0

Hence Rolle's Theorem varified.