Question

If sin(x-(3pi/2))=-4/5,
pi/2 12 years ago

Answer 1

as x is in the second quadrant its sine is 4/5

sin x = 2 sin(x/2)cos(x/2)

so sin(x/2)*cos(x/2) = sin x / 2 = 2/5

Answer 2

Oh man thank you, here I was making up formulas, I completely forgot sinx=2sin(x/2)cos(x/2). Just a small correction that sinx=3/5 so the final result is 3/10.

Answer 3

yw

Answer 4

ah yes 3/5 is correct ...

Answer 5

- for sin x