Respuesta :

[tex]\bf \textit{symmetry identites}\\\\ cos(-\theta)=cos(\theta)\\\\ -----------------------------\\\\ cos(-x)tan(x)\implies cos(-x)\cdot \cfrac{sin(x)}{cos(x)}\\\\\\ cos(x)\cdot \cfrac{sin(x)}{cos(x)}\implies sin(x)[/tex]
RELAXING NOICE
Relax