The function y=-16t^2+8t represents the height y (in feet) of a grasshopper jumping straight up from the ground t seconds after the start of the jump. After how many seconds is the grasshopper 1 foot off the ground?
You want to solve the given equation for y = 1
-16t^2+8t-1 = 0 solve for t using quadratic formula a = -16 b = 8 c = -1
t= 1/4 sec