Question

Given sinθ =3/5 and (π/2<θ<π), how do you find sine (2π)?

I do understand how the triangle will be in the second quadrant.

Answer 1

`sin2theta=-24/25`

Explanation:

`"Do you mean "sin2theta?`

As `sintheta=3/5` and `pi/2 < theta < pi`, `theta` lies in second quadrant and `costheta` is negative.

Therefore `costheta=-sqrt(1-(3/5)^2)`

= `-sqrt(1-9/25)=-4/5`

Hence `sin2theta=2sinthetacostheta=2*3/5*(-4/5)=-24/25`