The section I understood the most this week is section 8 – 5. It is about using identities to get the same trig function in a equation. If that is not possible, then you can change everything to tangent and cotangent by sin / cos or cos / sin. Follow all inverse rules when working these problems. The things you can not do when working these problems is dividing by a trig function when you try to cancel things. You can not cancel the inside of the trig functions. If you have sin(9x)/ 9, you can not cancel the 9’s. you also can not divide and cancel cos^2x=cosx.
Example 1:
1. Sec^2 theta = 16
2. Square root(sec^2 theta) = square root(16)
3. Sec theta = 4
4. Theta = sec^-1 (4)
5. Sec^-1 is located in the first and second quadrant.
6. Theta = 75.5 degrees, 104.5 degrees.
This section was overall pretty easy once you understand it.