trig
posted by Aly on .
If
cot(x) = −19/18
,
where x is in Quadrant IV, what is the exact value of sin(2x)?

tan x = 18/19
hypotenuse = sqrt (18^2+19^2)
= sqrt (324+361)
= sqrt(685)
sin x = 18/sqrt(685)
cos x = +19/sqrt(685)
sin (2x) = 2 sin x cos x
= 2*18*19/685