xcuse me plz explain me what is ROLLES THEOREM and its application.Also suggest me if there is any online video lecture on this topic.

let f(x) is functions which has many turnings

take two points  (a,f(a)) and (b,f(b))

where f(a) =f(b)

a is not equal to b

as by drawing a graph we can understand that the two points are possible only when graph has a turning between a and b

so at the turning point differentiation is equal to zero

as there canbe more than one turning many pts are possible where differentiation is zero..

sothere exist atleast one pt where differentiation is zero this is rolle''s theorem