Answer
$y(x)=4^x$
Work Step by Step
Observe that the graph is of the form $y=b^x$. To find the equation of the graph, we need to find the value of $b$. To find this value, we substitute values from the point $(1,4)$. We get $b=4$. Thus the equation is $y(x)=4^x$.
$y=b^x\rightarrow4=b^1\rightarrow{b}=4$
$y(x)=4^x$