Question

упростите 

a)(1-cos2d)ctgd.б)cos6dдробьcos2d-sin6dдробьsin2d+2

 

Answer 1

$(1-cos2x) * ctgx = (1 - (cos^{2}x - sin^{2}x)) * ctgx = </var><var>(1 - cos^{2}x + sin^{2}x) * ctgx = (sin^{2}x + sin^{2}x) * ctgx = 2sin^{2}x *ctgx = 2 * sinx * sinx * cosx/sinx = 2sinxcosx = sin2x$

второе не поняла как-то..)