Monday

March 30, 2015

March 30, 2015

Posted by **jeethu** on Tuesday, January 15, 2013 at 12:19am.

- maths -
**Steve**, Tuesday, January 15, 2013 at 12:08pmin QII, cosy is negative

cosx = -4/5

siny = 5/13

now, just plug in the formulas. for example

sin(x+y) = sinx*cosy+cosx*siny

= (3/5)(-12/13)+(-4/5)(5/13)

= -36/65 - 20/65

= -56/65

**Answer this Question**

**Related Questions**

math - If sinx=3/5,cosy=-12/13,where x and y both lie in 2nd quad.Find the value...

trig - -Find sin(x+y), cos(x-y), tan(x+y) and the quadrant of x+y sinx=-3/5, ...

maths --. - If sin theeta=3/5 , cos alpha= -12/13 and theeta,alpha both lie in ...

Urgent - draw an angle x in the 1st quadrant with sinx=3/5, and an angle y in ...

Trig - given that sinx=3/4 and cosy=-5/13 and both x and y are in quadrant II, ...

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

pre calc - Find the exact value of sin(x-y) if sinx=-3/5 in Quadrant III and ...

Trigonometry - Prove the following trigonometric identities. please give a ...

calc - what is the derivative of sinx- cosy = 0 in its simplest form? I got to ...

maths (trigonometry) - please solve these if possible Q1. If sinx +siny=3(cosy-...