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September 2, 2014

September 2, 2014

Posted by **pleasehelp!** on Friday, March 4, 2011 at 12:54am.

2. Find the exact value of sin (α-β) if sina=4/5 and cos β= -9/41 terminal side of α lies in I and terminal side of β lies in III

3. If cosx=1/12 and sinx > 0, find tan2x

thankyou!

- PRE CALC -
**agrin04**, Friday, March 4, 2011 at 2:11am1. tan(36 - 2) = tan 34

2. sin ? = 4/5 --> cos ? = 3/5

cos ? = -9/41 --> sin ? = -40/41

sin(?-?) = sin?*cos? - cos?*sin? = ?

3. tan x = sqrt(143)

tan 2x = 2tanx/(1 - tan^2(x)) = ?

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