1. (sinᴓ + cosᴓ)² = 1+sin2ᴓ
2.cot2ᴓ=cos²ᴓ-sin²ᴓ over 2sinᴓ cosᴓ
3.tan2ᴓ=2 over cotᴓ-tanᴓ
Last edited by TJ123456; May 3rd 2009 at 03:57 PM.
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can someone please help?
Originally Posted by TJ123456 ᴓ=pheta
1. (sinᴓ + cosᴓ)² = 1+sin²ᴓ
2.cotᴓ=cos²ᴓ-sin²ᴓ over 2sinᴓ cosᴓ
3.tan2ᴓ=2 over cotᴓ-tanᴓ 1. Expand like you would any other function:
It would appear number 1 is not an identity. (try 90deg)
2 is not an identity either (try 45 degrees)
Looking at the denominator:
The original expression becomes:
Last edited by e^(i*pi); May 3rd 2009 at 04:08 PM.
Reason: misread a minus sign
thanks,my teacher said they would all work,so i went back and check my typing(i was in hurry this morning) and i did made a typo,so thats why they didnt work,i edit them just now if u wanna help again but you dont have too,again thanks man
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