The function f (t) = - 18t2 + 42t + 36 represents the height of the path traced by an airborne flying disc, where t is the time in seconds. How many seconds will it take the flying disc to complete its path?

To complete path means the disc lands on the ground, the height f (t) = 0

-18t²+42t+36=0

simplify by dividing - 6: 3t²-7t-6=0

facotor: (t-3) (3t+2) = 0

t=3 or t=-2/3 (discard this negative one because time cannot be negative.

so the answer is 3 seconds.

Wait I will figure it out