1. [tex]f(x)=e^{-2x}[/tex] is continuous and differentiable everywhere, so it is continuous on [0, 1] and differentiable on (0, 1), and the MVT is satisfied.
We have
[tex]f'(x)=-2e^{-2x}[/tex]
and the MVT says there is some [tex]c\in(0,1)[/tex] such that
[tex]f'(c)=\dfrac{f(1)-f(0)}{1-0}[/tex]
We find that
[tex]-2e^{-2c}=e^{-2}-1\implies c=1+\ln\sqrt{\dfrac2{e^2-1}}[/tex]
2. Rolle's theorem has the same conditions as the mean value theorem, with the added condition that [tex]f(x)[/tex] attains the same values at both endpoints of the interval in question.
Here, [tex]f(x)[/tex] is a polynomial, so it's continuous and differentiable everywhere, and [tex]f(0)=9[/tex] and [tex]f(3)=9[/tex], so Rolle's theorem is satisfied.
It then says that there exists [tex]c\in(0,3)[/tex] such that
[tex]f'(c)=\dfrac{f(3)-f(0)}{3-0}=0[/tex]
The derivative is
[tex]f'(x)=3x^2-2x-6[/tex]
and we have
[tex]3c^2-2c-6=0\implies c=\dfrac{1\pm\sqrt{19}}3[/tex]
Take the solution with the positive square root (the other solution is negative) so that
[tex]c=\dfrac{1+\sqrt{19}}3[/tex]