Question

13sin469градусов-8cos341 градусов/cos 19 градусов= ?

Answer 1

$frac{13 sin469^{o}-8 cos341^{o}}{cos19^{o}}=frac{13 sin(360^{o}+109^{o})-8 cos(360^{o}-19^{o})}{cos19^{o}}=\ \ =frac{13 sin109^{o}-(-8 cos19^{o})}{cos19^{o}} = frac{13 sin(90^{o}+19^{o})+8 cos19^{o}}{cos19^{o}} = \ \=frac{13 cos19^{o}+8 cos19^{o}}{cos19^{o}} = frac{21 cos19^{o}}{cos19^{o}} = 21$