Pre-Calc 12 Section 6.2 part 2

Sum, Difference and Double-Angle Identities Part 2
(actually only the double-angle identities)

Oh....there is also a mistake in example #5...see if you can spot it. I made a boo boo when drawing the triangle for tangent A! Let's see if you really know what you are doing!

[yupengzhao]

Ah ha, found a mistake!
So around 20 min, where drawing the picture for tanA=3/4, the opposite should be (-3) and the adjacent should be (-4).
Since the drawing wasn't correct, the sinA and cosA values were also incorrect. What I got for part c) was 33/50.
鼓掌鼓掌鼓掌鼓掌鼓掌
O(∩_∩)O~

[yunfeichen]

strangle lolin example 4 and 15 mins lol