Question 832313
{{{cos(x)=2*sin(x)}}}
Square both sides,
{{{cos^2(x)=4sin^2(x)}}}
You know that,
{{{cos^2(x)+sin^2(x)=1}}}
{{{cos^2(x)=1-sin^2(x)}}}
Substitute,
{{{1-sin^2(x)=4sin^2(x)}}}
{{{5sin^2(x)=1}}}
{{{sin^2(x)=1/5}}}
{{{sin(x)=1/sqrt(5)=sqrt(5)/5}}}
Two solutions,
{{{x=26.6}}} degrees and {{{x=153.4}}} degrees