00:01
All right, in your question, you're dealing with the satellite above the earth, and it tells us that the satellite is 112 miles directly above the earth.
00:08
So this distance right here would be the 112.
00:11
You're told the angle here is 76 .8 degrees, and you're asked to find the radius of the earth.
00:20
So what i've done is i've went ahead and labeled the radius r, and we could set this problem up using a trig function.
00:30
Because the angle that we're looking at here 76 .8 is the angle opposite this side, and the 112 and the r combined represent the hypotenuse.
00:47
The trick function that relates the opposite side of a right triangle to the hypotenuse of the right triangle is sine.
00:57
So sign of 76 .8 degrees is going to equal the opposite side, which is r over the hypotenuse, which is r plus 112.
01:11
And now we can get a value for sign of 76 .8.
01:16
I'm going to do that first.
01:19
So using a calculator, make sure you're in degree mode.
01:23
And i'm going to type in sign of 76 .8.
01:27
This is going to be a long decimal.
01:30
And i'm going to try to be pretty accurate here, because this is intermediate work.
01:35
I don't want to round this too much to start...