Saturday

October 25, 2014

October 25, 2014

Posted by **Nan** on Friday, December 29, 2006 at 4:24pm.

cos u = 3/5; 0 < u < pi/2

cos v = 5/13; 3pi/2 < v < 2pi

Find:

sin (v + u)

cos (v - u)

tan (v + u)

First compute or list the cosine and sine of both u and v.

Then use the combination rules

sin (v + u) = sin u cos v + cos v sin u.

cos (v - u) = cos u cos v + sin u sin v

and

tan (u + v) = [tan u + tan v]/[1 - tan u tan v]

We got sin u = 4/5 & sin v = SQRT (7/13)

- Trig -
**qqq**, Saturday, November 29, 2008 at 7:54amif cos u=3/5

cos v=5/13

then sin u=4/5 and sin v=12/13

then sin(v+u)=sinv cos u+cos v sin u

sin(v+u)=56/65

cos(v-u)=63/65

Tan u=4/3 and tan v=12/5 then

tan(u+v)=-56/33

**Answer this Question**

**Related Questions**

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

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

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 ...

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

Trigonometry - Please review and tell me if i did something wrong. Find the ...

calculus - Differentiate. y= (cos x)^x u= cos x du= -sin x dx ln y = ln(cos x)^x...

Calc. - Differentiate. y= (cos x)^x u= cos x du= -sin x dx ln y = ln(cos x)^x ln...

trig 26 - simplify to a constant or trig func. 1. sec Ču-tan Ču/cos Čv+sin Čv ...