how should i start this

1 - cos^2 theta/ 1 + sin theta = (convert to) sin theta

please help

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- Dec 17th 2008, 01:48 AMxahjikatrigonometric identity proving need help
how should i start this

1 - cos^2 theta/ 1 + sin theta = (convert to) sin theta

please help - Dec 17th 2008, 01:58 AMChop Suey
- Dec 17th 2008, 02:02 AMxahjika
it says that

prove that it is an identity

1 - cos^2 theta/ 1 + sin theta = sin theta - Dec 17th 2008, 02:04 AMChop Suey
- Dec 17th 2008, 02:05 AMMush
That identity is not true. Are you sure you're written it correctly?

Edit: Ah right, I was reading it incorrectly also... nevermind. - Dec 17th 2008, 02:46 AMxahjika
so sorry i don't know that... i'm just copying what's on the board

- Dec 17th 2008, 03:12 AMxahjika
- Dec 17th 2008, 06:34 AMxahjika
is this right?

red means canceled out

1 - sin^2 theta =

(1 - sin theta) (1 + sin theta)/ (1 + sin theta)=

1 - ( 1 - sin theta) = sin theta - Dec 17th 2008, 07:33 AMChop Suey