Practice problem
If f(x)=ax2+bx+cf(x)=ax^2+bx+cf(x)=ax2+bx+c is a quadratic function with a<0a<0a<0, what is the yyy-value of the vertex?
y=f(−ba)y=f(\frac{-b}{a})y=f(a−b)
y=−2aby=\frac{-2a}{b}y=b−2a
y=−b2ay=\frac{-b}{2a}y=2a−b
y=f(−b2a)y=f(\frac{-b}{2a})y=f(2a−b)
Type a concept, like “slope” or “photosynthesis”.