SOLUTION
The critical point is the point where the derivative of the function is equal to zero or undefined.
So, for
[tex]f(x)=2^xcos(x)\text{ }[/tex]
the derivative becomes
[tex]\begin{gathered} \frac{d}{dx}(2^xcos(x)) \\ apply\text{ the product rule} \\ \frac{d}{dx}(2^x)cos(x)+\frac{d}{dx}(cos(x))2^x \\ 2^xln(2)cos(x)+(-sin(x))(2^x) \\ =ln(2)2^xcos(x)-2^xsin(x) \end{gathered}[/tex]
Setting the derivative to zero, we have
