Friday

September 19, 2014

September 19, 2014

Posted by **sayan** on Wednesday, April 11, 2012 at 11:56pm.

- maths -
**Steve**, Thursday, April 12, 2012 at 10:36amsin a = 4/5

sin b = -24/25

cos b = -7/25

cos(a+b) = cosa*cosb-sina*sinb

= (-3/5)(-7/25) - (4/5)(-24/25)

= 21/125 + 96/125

= 117/125

now apply the formula for sin(a-b) the same way.

**Answer this Question**

**Related Questions**

advanced functions - Angle a lies in the second quadrant and sina=7/25. a) ...

Trig - The angle 2x lies in the fourth quadrant such that cos2x=8/17. 1.Which ...

math - um take home test...i have no idea what im doing always sometimes never 1...

Math!!! - angle x is in the second quadrant and angel y is in the first quadrant...

Math - Angle x is in the second quadrant and angle y is in the first quadrant ...

trig - Consider the angle in standard position whose measure is radians. The ...

Math homework help - Use half angle identities to find exact value. Given tan ...

trig - Angle x is in the second quadrant and angle y is in the first quadrant ...

trig - Angle x is in the second quadrant and angle y is in the first quadrant ...

Trig - The angle 2x lies in the fourth quadrant such that cos2x=8/17. 1.Which ...