How do I find the exact solutions algebraically for the following equation?
sin 2x sin x = cos x
Any help is appreciated.
Without knowing the domain you could potentially be dividing by 0 when cos(x)=0 if you cancel. It is better to take cos(x) from both sides and factor out cos(x)
Either or
This should give 3 principal solutions and there may be more or less depending on the domain (usually )