Jane and jill want their mom to ride the rollercoaster with them, but she thinks it will be too fast. she asks the girls to find out how fast the rollercoaster will be travelling. they find out that the speed of the rollercoaster, in miles per hour, is modeled by the function g(x) = x4 − 4x2 + 7x − 8, where x is time measured in seconds. how fast is the rollercoaster travelling at 2 seconds?
6 miles per hour
22 miles per hour
26 miles per hour
54 miles per hour