## Functions Modeling Change: A Preparation for Calculus, 5th Edition

Expand the function to get $$y=5(x-3)(x-3)=5(x^2-3x-3x+9)=5(x^2-6x+9)$$ $$y=5x^2-30x+45$$ Since the coefficient to the $x^2$ term is positive, the function is concave up.