Friday

April 17, 2015

April 17, 2015

Posted by **chris** on Thursday, November 18, 2010 at 10:33pm.

- trig -
**Reiny**, Thursday, November 18, 2010 at 10:43pmdo you see the pattern

cos(A + B) = cosAcosB - sinAsinB here ?

also remember that cos(-A) = cos (A)

give it a try

**Answer this Question**

**Related Questions**

Math - 3. find the four angles that define the fourth root of z1=1+ sqrt3*i z...

Trigonometry - If cos(a)=1/2 and sin(b)=2/3, find sin(a+b), if 1) Both angles ...

TRIG! - Posted by hayden on Monday, February 23, 2009 at 4:05pm. sin^6 x + cos^6...

Precalculus/Trig 6 - Find the exact value of the following trigonometric ...

Homework Help Calculus - Find the linear approximation L(x)of the function f(x)=...

trig - Reduce the following to the sine or cosine of one angle: (i) sin145*cos75...

tigonometry - expres the following as sums and differences of sines or cosines ...

Math - Given that cos 13pi/18=sin y, first express 13pi/18 as a sum of pi/2 and ...

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

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