Question

$\sin 55-\cos {35}^{\circ }$ expressed in terms of angle between ${\theta }^{\circ }$ and ${45}^{\circ }$ is

• A. $0$
• B. $1$
• C. $2$
• D. $3$

Answer 1

The correct option is A $0$

We know, $\sin \theta =\left(\cos {90}^o-\theta \right)$

to find,

$\sin {55}^o-\cos {35}^o$

$\sin {55}^o=\cos \left({90}^o-{55}^o\right)=\cos {35}^o$

$\sin {55}^o=\cos {35}^o$

Substituting $\sin {55}^o=\cos {35}^o$

$\cos {35}^o-\cos {35}^o=0$