mathematics
posted by Yuli .
given tanθ= 2√10/3 and π/2<θ< π find:
a.sin2θ
b.tan θ/2
could some1 help me with these 2 they're the only ones i couldn't get

OK so it is in the second quadrant and the reference angle is arctan 2√10/3.
The ref. angle is arctan2.1082 = 64.6 degrees.
The angle itself is 180 64.6 = 115.4 degrees = 2.0137 radians.
use that to compute (a) and (b)