Question

3 sin x + 5 cos x = 0

Answer 1

3sinx=-5cosx

3sinx/cosx = -5
tan x = -5/3

I don't have a calculator, but you should know how to solve from there

Answer 2

Subtract the 5cos(x)=>3sin(x)=-5cos(x)
Divide by -5cos(x)=> (-3/5)tan(x)=1
Multiply by -5/3=>tan(x)=-5/3=>x=arctan(-5/3)

Answer 3

I've done it too, and it's ok.

Answer 4

k, thnks guyz/

Answer 5

No problem.