Who needs a teacher? Just think a bit. Where is the ball to start with? At the top of the cliff.
That's when t=0.
So, plug in 0 for t and evaluate.
A firework is launched from a cliff overlooking the ocean. The elevation of the firework shell, in feet above sea level, t seconds after launch is given by the expression -16t^2+157t+63. How high is the top of the cliff, in feet above sea level.
We just started and my teacher wasn't here today.
2 answers
63
1 answer