## BlingBlong Group Title Solve cos^(2)(x) - 3sin(x) = 3 for x on [0, 2pi] So I have simplified the function down to (-sin(x) - 2)(sin(x) + 1) = 0 or (-sin(x) -1)(sin(x) + 2) = 0 I have determined x = 3pi/2 as sin(3pi/2) = 1/2 Is that the only value possible As I don't think there is a value in the domain of this function that I could use to solve (sin(x) + 2) or (-sin(x) - 2) I could imput arcsin(2) but would that be wrong and if so why? 2 years ago 2 years ago

1. watchmath Group Title

because the value of sin is at most 1. SO arcsin(2) is undefined. So the solutions only comes from -sin x -1 =0

2. BlingBlong Group Title

sin(3pi/2) = -1

3. BlingBlong Group Title

made a typo. so I'm correct.

4. watchmath Group Title

yes $$e\pi/2$$ is the only answer

5. BlingBlong Group Title

so I should always adhere to the range of the unit circle when dealing with trig functions?

6. watchmath Group Title

I mean $$3\pi/2$$

7. BlingBlong Group Title

yeah I was wondering lol