00:01
Okay, first step.
00:01
Let's just rearrange this.
00:03
So i'm going to take away 2 from both sides.
00:05
So 7 then and take away cos from both sides and get 8 cos theta.
00:11
So like terms together, 9 cos minus cos, 8 cause and 9 minus 2.
00:17
That means then that cosine theta must be 7 over 8.
00:22
Just divide both sides by 8.
00:26
We're in the first quadrant.
00:29
So all i do here then define theta.
00:31
Is inverse cosine of 7 over 8.
00:37
And for the first step, make sure you're in radian mode on the calculator, radians.
00:42
Then you press second cosine to get inverse cosine, and then type in 7 divided by 8...