The height h (in inches) above the water of a pelican before a dive is modeled by h=-16t^2+70t+50, where t is time (in seconds)
a) when does the pelican enter the water
b)how high above the water is the pelican at time t=0 seconds

ANSWER

a) 5 seconds.

b) 50 inches.

EXPLANATION

The height of the pelican is modeled by,

The pelican enters the when

Divide through by negative 2,

Factor to obtain

This implies that,

Time cannot be negative, therefore the water after 5 seconds.

B) The height of the pelican is modeled by

When

The pelican was 50 inches above the water at time t=0.

225x²+4=0

225x²=0-4

225x²=-4

x²=-4/225

x=±√-4/225