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January 26, 2015

January 26, 2015

Posted by **Ryan** on Tuesday, October 11, 2011 at 8:54pm.

- trig -
**Reiny**, Tuesday, October 11, 2011 at 10:30pmDid you recognize the 7-24-25 right-angled triangle?

then sin B = -7/25

cos B = -24/25

sin 2B = 2sinBcosB = 2(-7/25)(-24/25) = 336/625

cos2B = cos^2B - sin^2B = 576/625- 49/625 = 527/625

tan2B = sin2B/cos2B = (336/625)÷(527/625) = 336/527

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