00:01
Okay, so you are given the equation d is equal to v.
00:07
Sub not squared, sign of theta, cosine of theta over 16.
00:17
And the distance depends on the initial velocity and the angle above the horizontal from which you throw the object.
00:31
And you and your friend are throwing a baseball back and forth.
00:36
If you are given an initial velocity of 180 feet per second, at what angle of elevation to the nearest degree should you direct your throat so that it can easily be caught by your friend 170 feet away? so they give you d and they give you v not, and you're being asked to find theta.
01:06
So right now it may seem like a little much because you have sign and cosine.
01:11
But remember that sign and cosine can be written, rewritten as sign of 2 theta over 2.
01:29
This is equal to sine of theta times cosine of theta.
01:35
And that is your product.
01:38
Identity.
01:40
So that means the distance is equal to v0 squared sine of 2 theta over 32.
01:58
So solving for sine of 2 theta, sine of 2 theta is equal to 32 over v0 squared.
02:14
So then 2 theta is equal to the inverse sign of 32...