\"\"

\

The function is \"\"\"\" .

\

The function \"\" is continuous over closed interval \"\" , and differentiable on the open interval \"\" .

\

Therefore mean value theorem can be applied .

\

So, there exists at least one number \"\" in \"\" such that \"\" .

\

The slope of the secant line through \"\" and  \"\" is

\

\"\" 

\

\"\"

\

\"\"

\

\"\"

\

Apply the derivative .

\

\"\"

\

\"\"

\

\"\"

\

\"\"

\

\"\"

\

\"\"

\

 \"\".