Question

If tan A=2 sin A .Then find the value of A, given 0<\= A <\=360.

Answer 1

`tan(A)=2sin(A) \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ \cfrac{sin(A)}{cos(A)}~~ = ~~2sin(A)\implies sin(A)=2sin(A)cos(A) \\\\\\ sin(A)-2sin(A)cos(A)=0\implies sin(A)[ ~~ 1~~ - ~~2cos(A) ~~ ]=0 \\\\[-0.35em] ~\dotfill\\\\ sin(A)=0\implies A=sin^(-1)(0)\implies A= \begin{cases} 0\\ 180^o\\ 360^o \end{cases} \\\\[-0.35em] ~\dotfill\\\\ 1-2cos(A)=0\implies 1=2cos(A)\implies \cfrac{1}{2}=cos(A) \\\\\\ cos^(-1)\left( \cfrac{1}{2} \right)=A\implies A= \begin{cases} 60^o\\ 300^o \end{cases}`