Question

Transformați in produs tg 130 grade + tg 50 grade

Answer 1

Salut,

$tga+tgb=\dfrac{sina}{cosa}+\dfrac{sinb}{cosb}=\dfrac{sina\cdot cosb+cosa\cdot sinb}{cosa\cdot cosb}=\dfrac{sin(a+b)}{cosa\cdot cosb}.\\\\tg130^{\circ}+tg50^{\circ}=\dfrac{sin(130^{\circ}+50^{\circ})}{cos(130^{\circ})\cdot cos(50^{\circ})}=0.$

Green eyes.