Question

ALGUEM ME SOCORRA!!!!!!


SENDO X = 60º,  DETERMINE O VALOR DA EXPRESSAO;
      
                 COS 2X+SEN 7X/2+TG 5X

Answer 1

$cos2x+sen\frac{7x}{2}+tg5x$

Vamos apenas substituir o "x" e calcular separadamente:

$cos2x \\\\ cos2 \cdot 60\° \\\\ cos120\° = -cos60\° = \boxed{-\frac{1}{2}}$


$sen\frac{7x}{2} \\\\ sen\frac{7 \cdot 60\°}{2} \\\\ sen\frac{420\°}{2} \\\\ sen210\° = -sen30\° = \boxed{-\frac{1}{2}}$


$tg5x \\\\ tg5 \cdot 60\° \\\\ tg300\° = -tg60\° = \boxed{-\sqrt{3}}$


$cos2x+sen\frac{7x}{2}+tg5x \\\\ cos120\°+sen210\°+tg300\° \\\\ -\frac{1}{2}-\frac{1}{2}-\sqrt{3} \\\\ -\frac{2}{2}-\sqrt{3} \\\\ \boxed{\boxed{-1-\sqrt{3}}}$