Derivative of velocity then critical points question (Optimization problem)
(1 pt) A University of Rochester student decided to depart from Earth after his graduation to find work on Mars. Before building a shuttle, he conducted careful calculations. A model for the velocity of the shuttle, from liftoff at t = 0 s until the solid rocket boosters were jettisoned at t = 63.4 s, is given by
(in feet per second). Using this model, estimate
the absolute maximum value
and absolute minimum value
of the ACCELERATION of the shuttle between liftoff and the jettisoning of the boosters.
My problem: (My work is attached) When I attempt to use the quadratic formula to solve for x on the derivative function of velocity (=acceleration function), the inside of the square root is negative and I therefore cannot take the square root of it. Can someone please help me out?