Friday

August 22, 2014

August 22, 2014

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

**Related Questions**

Trig - Given: cos u = 3/5; 0 < u < pi/2 cos v = 5/13; 3pi/2 < v < ...

Trig Identities - Proving identities: 1) 1+ 1/tan^2x = 1/sin^2x 2) 2sin^2 x-1 = ...

math - Use the exact values of the sin, cos and tan of pi/3 and pi/6, and the ...

math - Use the exact values of the sin, cos and tan of pi/3 and pi/6, and the ...

precalculus - For each of the following determine whether or not it is an ...

Mathematics - Trigonometric Identities - Let y represent theta Prove: 1 + 1/tan^...

Pre-calc help please!!! - 1) tan(sin^-1(5/6)-cos^-1(1/7) 2) tan(è + ); cos...

trig 26 - simplify to a constant or trig func. 1. sec ²u-tan ²u/cos ²v+sin ²v ...

Trig Question - Given that tan x= -3/4 and x is in the second quadrant. Find sin...

Trigonometry - 1.Solve tan^2x + tan x – 1 = 0 for the principal value(s) to two ...