The height h, in metres of a football is given by the relation h= -0.02d^2 +d, where d represents the horizontal distance, in metres, that the ball travels.
Question is - How far does the ball travel before it hits the ground.
Confused O.o
I know that because we are finding the distance (d) we let h=0
i dont know what to do next.
Thank You
Question is - How far does the ball travel before it hits the ground.
Confused O.o
I know that because we are finding the distance (d) we let h=0
i dont know what to do next.
Thank You
-
Yes you are correct. Since we trying the figure out when the ball hits the ground, the height must equal zero. therefore you are left with 0 = -.02d^2 + d.
You can solve this in a few ways.
One is subbing this information into the quadratic equation, which is (-b +/- (b^2 - 4ac)^1/2) / 2a
that turns into (-1 +/- (1 + 0)^1/2) / -.04)
and that gives you two answer = 0, and 50. The extraneous root is 0. and so the answer is 50
Another way which is a lot easier is to just put it into a graph. set y= .02x^2 + x. And find the x intercept (y=0). the x value will be your answer.
You can solve this in a few ways.
One is subbing this information into the quadratic equation, which is (-b +/- (b^2 - 4ac)^1/2) / 2a
that turns into (-1 +/- (1 + 0)^1/2) / -.04)
and that gives you two answer = 0, and 50. The extraneous root is 0. and so the answer is 50
Another way which is a lot easier is to just put it into a graph. set y= .02x^2 + x. And find the x intercept (y=0). the x value will be your answer.