305. Find the value of the derivative of the function $y=2^{x}$ at the point $x=1$.
Solution. We find the derivative using formula XI: $y^{\prime}=2^{x} \ln 2$. We compute the particular value of the derivative at $x=1$:

$$
y^{\prime}(1)=\left(2^{x} \ln 2\right)_{x=1}=2 \ln 2=\ln 4 .
$$

306-311. Find the derivatives of the following functions: