Question

Evaluate :

$\frac{2cos{67}^o}{sin{23}^o}-\frac{tan{20}^o}{cot{50}^o}-cos{0}^o$

Answer 1

$\frac{2cos{67}^o}{sin{23}^o}-\frac{tan{20}^o}{cot{50}^o}-cos{0}^o$

$=\frac{2cos({90}^o-{23}^o)}{sin{23}^o}-\frac{tan({90}^o-{50}^o}{cot{50}^o}-cos{0}^o$

$=\frac{2sin{23}^o}{sin{23}^o}-\frac{cot{50}^o}{cot{50}^o}-cos{0}^o$

$=2\times 1-1-1=0$