Question

sin2x+cosx=0

Answer 1

sin(2x) = 2sin(x)cos(x)

After that, you can factor and solve.

Answer 2

Can you do it step by sorry please

Answer 3

*step

Answer 4

You need to be able to do that substitution.

sin(2x) + cos(x) = 0

By substitution, is equivalent to

2sin(x)cos(x) + cos(x) = 0

Now you go back to algebra. Factor the expression on the left hand side. We'll come back to trigonometry when you are done factoring and we remember why we are doing that.

Answer 5

I got cosx(2sinx)=0

Answer 6

Nice try. Remember the Distributive Property

2sin(x)cos(x) + cos(x) = 0

cos(x)(2sin(x) + 1) = 0

You have to believe this.