The function is continuous and
.
Mean value theorem for integrals:
\If
is continuous on
, then there exist a number
in
such that
.
Since the function is continuous on
, so by the mean value theorem, there exist a number
in
.
Such that
\
.
We have,
.
Substitue
in
.
.
From the above expression it is observed that there exist a number
in 
Such that
.
Therefore, the function value takes on the value
on
.
The function value takes on the value
atleast once on
.