document.write( "Question 509822: a missile is projected vertically upward from an underground bunker in such a way that t seconds after launch, it's s feet above the ground, where :
\n" ); document.write( " s(t)= -16t^2+800t-15.
\n" ); document.write( "a) how deep is the bunker?
\n" ); document.write( "b) when's the missile at its highest point?
\n" ); document.write( "c) what is the max height?
\n" ); document.write( "I got the answer of b) is 25s and c) is 9985 but i'm not sure. Thanks if tutors can help me \n" ); document.write( "
Algebra.Com's Answer #341619 by nerdybill(7384)\"\" \"About 
You can put this solution on YOUR website!
a missile is projected vertically upward from an underground bunker in such a way that t seconds after launch, it's s feet above the ground, where :
\n" ); document.write( "s(t)= -16t^2+800t-15.
\n" ); document.write( "a) how deep is the bunker?
\n" ); document.write( "15 feet
\n" ); document.write( "b) when's the missile at its highest point?
\n" ); document.write( "at vertex where
\n" ); document.write( "t = -b/(2a)
\n" ); document.write( "t = -800/(2(-16))
\n" ); document.write( "t = -800/(-32)
\n" ); document.write( "t = 25 seconds
\n" ); document.write( ".
\n" ); document.write( "c) what is the max height?
\n" ); document.write( "s(t)= -16t^2+800t-15.
\n" ); document.write( "s(25)= -16(25)^2+800(25)-15
\n" ); document.write( "s(25)= -10000+20000-15
\n" ); document.write( "s(25) = 9985 feet
\n" ); document.write( " \n" ); document.write( "
\n" );