0. sin 2x = cos 3x
1. sin 2x = sin (pi/2 - 3x) [because cos u = sin (pi/2 - u)]
2. [...]
Chat with our AI personalities
(1 - tan2x)/(1 + tan2x) = (1 - sin2x/cos2x)/(1 + sin2x/cos2x) = (cos2x - sin2x)/(cos2x + sin2x) = (cos2x - sin2x)/1 = (cos2x - sin2x) = cos(2x)
sin2x + c
Using x instead of theta, cos2x/cosec2x + cos4x = cos2x*sin2x + cos4x = cos2x*(sin2x + cos2x) = cos2x*1 = cos2x
cos(x)-cos(x)sin2(x)=[cos(x)][1-sin2(x)]cos(x)-cos(x)sin2(x)=[cos(x)][cos2(x)]cos(x)-cos(x)sin2(x)=cos3(x)
4 sin2x = 1. Then, (2sinx)2 = 1, 2sinx = ±1, and sinx = ±½. Whence, x = 90° or 270°; or, in radians, x = π/2 or 3π/2.