Question

prove: tan x/2 = the square root of 1-cosx/ 1+cosx

Answer 1

\[\cos x = 2 \cos^2 \frac{x}2 - 1\]\[\cos x = 1 - 2\sin^2\frac{x}2\]Now find the values of \(1-\cos x \) and \(1 + \cos x\), then divide.

Answer 2

- got beaten to it lol!

Answer 3

thanks!!

Answer 4

did you get it?

Answer 5

yes i was just stuck on the second part and i have another problem that i am stuck on its prove: csc^2 x/2 = 2secx/secx -1

Answer 6

@welshfella

Answer 7

yes i have done that already

Answer 8

sorry gtg right now

Answer 9

okay thanks anyway

Answer 10

im back

Answer 11

heck gtg again

Answer 12

convert to sines and cosines

1 / sin^2 (x/2) = (2/ cos x) / [(1/ cos x) - 1]

Answer 13

now use Parthkholis second identity for cos x and plug it into the right side and simplify
Its a bit messy but it will simplify to 1 / sin^2 (x/2)