9.4 #4 algebra

Question

h=-81t²+ct+a

Solve for t

 

t=__+/-__

Answer 1

h(t) = -81t^2 +ct + a

h = distance,usually h for height, t = time, c = initial velocity, a = initial position or initial height

-81t^2 + ct + a = 0

use the quadratic formula for h=at^2 + bt + c

where a=-81,b=c, c=1

t = -b/2a + or - (1/2a)sqr(b^2 - 4ac)

t = c/162 + or - (1/162)sqr(c^2 +4(81)a)

t = c/162 +/- (sqr(c^2+324a))/162