Question

The value of $\frac{\cos {12}^o-\sin {12}^o}{\cos {12}^o+\sin {12}^o}+\frac{\sin {147}^o}{\cos {147}^o}=$

• A. $1$
• B. $-1$
• C. $0$
• D. none of these

Answer 1

The correct option is C $0$

$\frac{cos{12}^{\circ }-cos(90-{12}^{\circ })}{cos{12}^{\circ }+cos(90-{12}^{\circ })}+\frac{sin{147}^{\circ }}{cos{147}^{\circ }}$

$\frac{cos{12}^{\circ }-cos{78}^{\circ }}{cos{12}^{\circ }+cos{78}^{\circ }}+\frac{sin(180-{33}^{\circ })}{cos(180-{33}^{\circ })}$

$\frac{+2sin{45}^{\circ }sin{33}^{\circ }}{2cos{45}^{\circ }cos{33}^{\circ }}+\frac{sin{33}^{\circ }}{-cos{33}^{\circ }}$

$\frac{1/\sqrt{2}}{1/\sqrt{2}}tan{33}^{\circ }-tan{33}^{\circ }$

$0$