00:08
So we are given the rectangular equation for the path of a projectile.
00:18
This equation is y equals 6 plus x minus 0 .08 x squared.
00:42
Now, in part a, we're asked to use the result of the previous exercise to find h, b, not, and theta, and define the parametric equations of the path.
00:59
Well, from exercise 98, we know that the rectangular equation must be of the form.
01:07
For a path of a projectile, negative 16, sikin squared theta over v0 squared times x squared plus tangent theta times x plus h.
01:26
And so if we compare this to our given rectangular equation, we see right away that h is equal to 6.
01:33
We know that negative 16 secund squared theta over v0 squared is equal to negative 0 .08 and the tangent theta is equal to 1.
01:59
So we already know what h is.
02:01
To find v .0, we're going to have to know theta, and you can find out theta from the third equation.
02:07
So from the third equation, we have the theta is the inverse tangent of 1, which is just, pi over 4 or 45 degrees.
02:24
And therefore we have v .0 squared.
02:29
This is equal to 16 secant squared of 45 degrees over 0 .08.
02:44
So that v .0, well, this is supposed to be positive, so it's the positive square root.
02:49
This is the positive square root of 16 secan squared of 45 degrees over 0 .0 .0.
02:57
08 and we've plugged this into a calculator.
03:11
The result is 20...