f(x)=-16x^2+32
x=time in sec.
y=heigh in feet
After about how many seconds were the keys 4 feet above the ground?
So when is f(x)=4
-16x^2+32=4
solve it and u get the result:
\(x= -sqrt(7)/2 , x= sqrt(7)/2\)
Only the positive result is the right answer, as theres no negative time.
Oh forget the first part:
When u want to have the heigh as x you need to rotate the graph by 90 against the clock.
Im not sure how to do this though.
When u rotate the graph every coordiante of x/y becomes y/-x. Example: 1/3 becomes 3/-1
That means in the equation every x becomes y and every y becomes -x.
-16x^2+32=f(x)
y is equal to f(x)
-16y^2+32=-x. I *-1
16y^2-32=x. I +32
16y^2= x+32. I/16
y^2. = x/16 + 2. I sqrt
\(y = \sqrt[2]{\frac{x}{16}} + \sqrt[2]{2}\)
\(f(x) = \sqrt[2]{\frac{x}{16}} + \sqrt[2]{2}\)
Im not sure if this answer is right.
