If sin θ = 2/3 , then what is sin ( − θ )

Answer 1

Sin(Theta) = 2/3 is in the first quadrant.

Then Sin(-Theta) would be in the 4th quadrant and the Sin is negative,

so Sin(-Theta) = -2/3

Answer 2

Sine is an odd function so:

sin(-θ) = - sin(θ) = -2/3