Posted by **jj reddick** on Friday, October 22, 2010 at 8:48pm.

Suppose that sin x = 1/5 and cos y = 2/3, and x and y are each angles in Quadrant 1. Determine sin(x+y).

- trig -
**Reiny**, Friday, October 22, 2010 at 10:53pm
make triangles for each case , then use Pythagoras

if sinx = 1/5, then cosx = √24/5

if cosy = 2/3 , the siny = √5/3

sin(x+y) = sinxcosy + cosxsiny

= (1/5)(2/3) + (√24/5)(√5/3)

= (2 + √120)/15

## Answer This Question

## Related Questions

- TRIG! - Posted by hayden on Monday, February 23, 2009 at 4:05pm. sin^6 x + cos^6...
- Trig - Find sin(s+t) and (s-t) if cos(s)= 1/5 and sin(t) = 3/5 and s and t are ...
- trig - suppose sin(x)=4/5 and cos(y)=-12/13, and x and y are in the second ...
- trig - suppose sin(x)=5/6, and x is in the first quadrant. Determine cos(x), sin...
- 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 ...
- Mathematics - Trigonometric Identities - Let y represent theta Prove: 1 + 1/tan^...
- Trig - Find cos(s+t) if cos s= -1/2 and sin t= 3/5, s and t are in quadrant II. ...
- algebra - Can someone please help me do this problem? That would be great! ...
- Trig - Given: cos u = 3/5; 0 < u < pi/2 cos v = 5/13; 3pi/2 < v < ...

More Related Questions