Question

Choose incorrect statement:

• A. $\sin \theta \text{is always positive for}{0}^{\circ }<\theta <{180}^{\circ }$
• B. $\cos \theta \text{is always positive for}{0}^{\circ }<\theta <{90}^{\circ }\text{and}{270}^{\circ }<\theta <{360}^{\circ }$
• C. $\tan \theta \text{is always positive for}{0}^{\circ }<\theta <{180}^{\circ }$
• D. $\text{cosec}\theta \text{is always positive for}{0}^{\circ }<\theta <{180}^{\circ }$

Answer 1

The correct option is C $\tan \theta \text{is always positive for}{0}^{\circ }<\theta <{180}^{\circ }$

$\tan \theta \text{is positive for}{0}^{\circ }<\theta <{90}^{\circ }$
$\text{and}{180}^{\circ }<\theta <{270}^{\circ }$
But $\tan \theta \text{is negative for}{90}^{\circ }<\theta <{180}^{\circ }$
$\text{and}{270}^{\circ }<\theta <{360}^{\circ }$

Option c is incorrect.