Question

Giải pt sau  

Giúp em vs ạ

Answer 1

ĐKXĐ: ...

\(tan2x.tanx+sinx\left(1+\dfrac{sinx.sin\dfrac{x}{2}}{cosx.cos\dfrac{x}{2}}\right)=0\)

\(\Leftrightarrow tan2x.tanx+sinx\left(\dfrac{cosx.cos\dfrac{x}{2}+sinx.sin\dfrac{x}{2}}{cosx.cos\dfrac{x}{2}}\right)=0\)

\(\Leftrightarrow tan2x.tanx+tanx.\dfrac{cos\left(x-\dfrac{x}{2}\right)}{cos\dfrac{x}{2}}=0\)

\(\Leftrightarrow tan2x.tanx+tanx=0\)

\(\Leftrightarrow tanx\left(tan2x+1\right)=0\)

\(\Leftrightarrow...\)