Question

What is the maximum height this rocket will reach?

Equation: h= -5t^2+30t+10

Please show me how to do this

Answer 1

max is the second coordinate of the vertex

Answer 2

the first coordinate of the vertex of \[y=ax^2+bx+c\] is \(-\frac{b}{2a}\) and the second coordinate is what you get when you replace \(x\) by the first coordinate

Answer 3

in your case \(a=-5,b=30\)

Answer 4

did you find \[-\frac{b}{2a}=-\frac{30}{2\times (-5)}\]?

Answer 5

I'm confused

Answer 6

me too
what are you confused about?

Answer 7

Oh wait I get it, sorry I got lost

Answer 8

ok good
it is brief

Answer 9

So all I have to do is solve this and I will get the max height? \[\frac{ 30 }{ 2(-5) }\]

Answer 10

you are off by a minus sign
it is \[-\frac{ 30 }{ 2(-5) }\]that will get you the input yes
then plug it in

Answer 11

i.e. plug in \(3\) for \(t\)

Answer 12

ok, thank you