Re: hmmm.
Hey, for the question containing sin2x -cos2x =0, therefore sin2x = cos2x. Then u change it to cos2x = cos (pi/2 - 2x) so then 2x = pi/2 - 2x. therefore, 4x = pi/2. therefore, look at the limits, 0<4x< 2pi. Therefore, 3pi/2 is also considered a solution. therefore, 4x = pi/2 and...