Solve the equation cos^2 A = sin^2 A + sinA when 0º≤A≤360º. There will me multiple answers.

A. 270
B.330
C.150
D.30

Question

Solve the equation cos^2 A = sin^2 A + sinA when 0º≤A≤360º. There will me multiple answers.

A. 270
B.330
C.150
D.30

anonymous · Answer

cos^2 A=1-sin^2 A
you will find a quadratic of sin A
solve that

anonymous · Answer

That is the part that confuses me. I'm unsure as to how i'd set it up to find the quadratic of sin A

anonymous · Answer

1-sin^2 A=sin^2 A+sinA
2sin^2 A+sin A-1=0

anonymous · Answer

I appreciate your help, but I'd be lying if I said I had the slightest clue as to what to do next.

anonymous · Answer

lol

anonymous · Answer

try to find out the solution of sinA
2sin^2 A + sinA-1=(2sinA-1)(sin A+1)
so, sinA=1/2 , -1
can you do the rest yourself?

anonymous · Answer

equate to 0 by the way^^

anonymous · Answer

Yeah, I think so. I just plug it in now right?

anonymous · Answer

yes

anonymous · Answer

So for my answer I got 56 thats not even an option fml

anonymous · Answer

sin 30=1/2
sin 270=-1

anonymous · Answer

Wow. Thank you. I appreciate it.