A Rocket is launched from the top of an 30 foot cliff with an initial velocity of 160 feet per second. The height, h of the rocket after t seconds is given by the equation h=16t2+160t+30.how long after the rocket is launched will it be 20 feet from the ground

secant-secant formula:

(whole secant) x (external part) =           (whole secant) x (external part)

(8+y-2) *8=                                           (y+4+6) *6

(y+6)*8 = (y+10) *6

distribute

8y+48 = 6y +60

subtract 6y from each side

2y +48 = 60

subtract 48 from each side

2y = 12

divide by 2

y = 6

sv =     (y+4+6)

sv   = 6+4+6

sv = 16