Graphing Quadratic Functions I need help with $f(x)=(x-3)^2$. My teacher said the $x$ intercept is $3$. I don't understand how it   can be positive $3$ when it is negative $3$ in the parenthesis.    

The $x$-intercepts are the points where $f(x)=0$, i.e., where the graph touches the $x$-axis. You have $f(3)=(3-3)^2=0$, so you have an $x$-intercept at $x=3$.
