Wednesday

July 23, 2014

July 23, 2014

Posted by **Anna** on Thursday, March 28, 2013 at 12:27pm.

- Trig -
**Steve**, Thursday, March 28, 2013 at 1:29pmSince sin = -12/13 in QIV, cos = 5/13

sec x/2 = 1/cos(x/2) = √(2/(1+cosx))

= √(1/(1+5/13)) = √(2/(18/13)) = √(26/18) = √13/3

**Related Questions**

Trigonometry - 4. Find the exact value for sin(x+y) if sinx=-4/5 and cos y = 15/...

trig - use a half-angle identity to find the exact value of tan 105 degrees.

trig - Solve cos x-1 = sin^2 x Find all solutions on the interval [0,2pi) a. x=...

pre-calc - Can someone help me find the exact value of 4csc(3pi/4)-cot(-pi/4)? ...

Trig - Find the exact value of tan 5pi/12 using the half-angle identity.

trig - Find the exact value by using a half-angle identity. cos 22.5 degrees

trig - find the exact value by using the appropriate half-angle identity: sin(...

Trigonometry - use the appropriate trig identity (sum and difference, half angle...

trig - Find the exact value. Without using a calculator a) cos (-17pi/6) b) sec...

Pre Cal. - 1. Use half-angle identity to find the exact value of cos165. MY ...