Using the double angle formula, we can find sin2x and cos2x:
sin2x = 2sinxcosx
cos2x = cos2x - sin2x
Therefore,
sin2x = 2(4/5)(-3/5) = -24/25
cos2x = (4/5)^2 - (-24/25)^2 = -7/25
sinx = 4/5 and x terminates in Quadrant II
Find sin2x and cos2x
How to get the answers, which are sin2x = -24/25, cos2x = -7/25?
1 answer
1 answer