Question

if sinX=-4/5 and cosY=7/25 and it is lies in 3rd quadrant ,then find the values of sin(X-Y)​

Answer 1

Answer:

not it can be lied in 3rd quadrant coz in 3rd quadrant cos Y is negative.

sin (x-y)= sin x cos y -sin y cos x

cos^2 y +sin^2 y=1

49/625+sin^2. y=1

sin. y =24/25

in the same way we can find cos x =3/5

so putting value of angles in our formula,

sin(x-y) = (-4/5)(-7/25) - (24/25)(3/5)

=28/125-72/125

=-44/125

hope it helps u dear ☺️☺️☺️