Friday

April 25, 2014

April 25, 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.

**Related Questions**

maths - In triangle ABC angle B > angle C if AM is the bisector of angle BAC...

Algebra - Rays PQ and QR are perpendicular. Point S lies in the interior of ...

Algebra - Rays PQ and QR are perpendicular. Point S lies in the interior of ...

geometry - I"m stuck on this question "Rays PQ and QR ae perpendicular.Point S ...

math - the second angle of a triangle is twice the first angle. The third angle ...

Geometry - Rays PQ and QR are perpendicular. p;oint S lies in the interior of ...

geometry - Rays PQ and QR are perpindicular. Point S lies i the interior of ...

Math - In a triangle, one angle is twice the measure of the second angle. The ...

maths --plse help me.. - In a pentagon ABCDE, angle B = 168, angle C:angleD = 23...

maths - in triangle abc if ab=bc then angle a = angle c or angle a = angle b