Answer:
1 seconds after being thrown, the stone reaches its max height
Step-by-step explanation:
The parabolic (quadratic) equation is:
[tex]h(x)=-5(x-1)^2+45[/tex]
Lets expand this in the form [tex]ax^2+bx+c[/tex], so we have:
[tex]h(x)=-5(x-1)^2+45\\h(x)=-5(x^2-2x+1)+45\\h(x)=-5x^2+10x-5+45\\h(x)=-5x^2+10x+40[/tex]
We can say the values of a,b, and c, now to be:
a = -5
b = 10
c = 40
The number of seconds at which the max would occur is given by the point, x, at:
[tex]x=-\frac{b}{2a}[/tex]
We know a and b, let's find the seconds, x,
[tex]x=-\frac{b}{2a}=-\frac{10}{2(-5)}=-\frac{10}{-10}=--1=1[/tex]
Hence,
1 seconds after being thrown, the stone reach its max height
