another trig problem

[xc630]

Hi I'm pretty sure i got one answer but need help with another part of the problem

The problem is:

cos x squared -3sin x=3

I got this:

1 - sin squared x -3sin x = 3

sin squared x + 3 sin x + 2 = 0
(sin x+1) (sin x +2) = 0
sin x =-1
sin x= -2

The sin x=-1 eventually gives me an answer of 270 degrees but the sin=-2 comes up as error domain on my calculator. The answer has to be between 0 and 360 degrees. How do I do the sin x = -2 part?

Plus how do you write "squared" using the keyboard?

Thanks

 

[Unco]

G'day, Xc630.

Your work is great.

sin(x) has a range from -1 to 1, so we can throw the sin(x)=-2 solution out.

sin(x)=-1 is the only possible solution. Solve for x in the required domain.

"Squared" can be written as ^2. Such as cos^2(x), meaning (cos(x))^2.