Trigonometric Identities Question 257
Question: $ \tan \frac{A}{2} $ is equal to
Options:
A) $ \pm \sqrt{\frac{1-\sin A}{1+\sin A}} $
B) $ \pm \sqrt{\frac{1+\sin A}{1-\sin A}} $
C) $ \pm \sqrt{\frac{1-\cos A}{1+\cos A}} $
D) $ \pm \sqrt{\frac{1+\cos A}{1-\cos A}} $
Show Answer
Answer:
Correct Answer: C
Solution:
$ \tan ( \frac{A}{2} )=\frac{\sin (A/2)}{\cos (A/2)}=\pm \sqrt{\frac{(1-\cos A)/2}{(1+\cos A)/2}}=\pm \sqrt{\frac{1-\cos A}{1+\cos A}} $ .
BETA
