Your answer to the second problem is correct, you just have to simplify it further. .
I don't understand what you did on the first problem. You need to find right?
There are two equations in my HW that im having trouble with. They happen to be next to each other so I took a picture.
They are separated by a white line, the answer I got is in blue and the answer the book gives is in red.
Really appreciate the assistance, as I have a test tomorrow and this stuff will be included.
First one is half angle, second is double..
What am I missing here? The formulas are correct, and I believe I'm doing them right.
Thanks for the response, I feel stupid now
For the first one, yes we're given
Then you need to find or as you said .
I made the assumption that since that and .
So i substituted those into a tangent formula and ended up with the answer which I circled in blue.
Ok, I see where you went wrong. You can't make that assumption. Sine can't equal the because sine is always less than 1. To solve this one, I would just use the formula for the tangent of twice an angle:
If we let then . Therefore:
If you do the algebra you should obtain a quadratic equation where you can solve for