Problema Solution
1. h(t)=9.8t^2-10t+210 after how many seconds will the stone hit the ground, round to the nearest hundredth's place.
2. f(x)=x^2-12x+36 quadratic function find the value of x
Answer provided by our tutors
I'll tell you the answer first. It is 4.147 seconds.
Now the method, it is very simple.
You know the height of the building, it is 210 metres. You can verify it by substituting t=0 in the equation for height.
Now you need to find the time the stone will hit the ground. Whatever the time may be, when it will hit the ground, "h" will be zero. So you get the time in seconds by substituting h=0 in the equation, and solving for a quadratic equation in terms of "t".
2)
0=x^2-12x-27
0=(x-9)(x-3)
x=9,3