Question

What is the domain and range of the quadratic equation y = –2x2 – 32x – 126?

Domain: All Real Numbers
Range: y greater than or equal to –8

Domain: All Real Numbers
Range: y less than or greater to –8

Domain: All Real Numbers
Range: y less than or greater to 2

Domain: All Real Numbers
Range: y greater than or equal to 2

Answer 1

for a parabola equation of the type \(\bf y = ax^2+bx+c\) you can always find the vertex at the coordinates of \(\bf \left(-\cfrac{b}{2a}\quad ,\quad c-\cfrac{b^2}{4a}\right)\)

so find the vertex first