Find sin2x for each given the following condition:
a) sin x = 4/5 for 90^{o} < x < 180^{o}
b)tan x = -2 for 3pi/2 < x < 2pi
Hello, alejandro!
We are given: .
Angle is in a right triangle with:
Pythagorus says:
Since in Quadrant 2,
Identity: .
Therefore: .
Since is in Quadrant 4, we have: .
Angle is in a right triangle with:
Pythagorus says: .
Therefore: .