Lesson 7.2 - Solving Trigonometric Equations Algebraically

Solving Trigonometric Equations Algebraically

[gaming__pigg]

I needed this... my teacher just doesn't explain it as well as you do.

[YihanXia]

It may be helpful to specify that cos^2(x) is equal to (cos(x))^2, not cos(x^2). Got stuck on that thinking that they should all be the same, but getting different answers on my calculator.

[jason_rivera]

Question @12:40:
cos inverse of (-2/3) is giving me 2.3 on my calculator but your answer is 0.84.

Is there something wrong with my calculator?

[jason_rivera]

Also, @17:30, why did you get the positive of (square root of 2)/5 instead of negative(square root of 2)/5?

[williamwimberly]

Wouldn't you subtract the whole left or right side? So 2sinx -2 =0, sinx = -1? So -90°? In example 1.