Вопрос пользователя:
упростите
a)(1-cos2d)ctgd.б)cos6dдробьcos2d-sin6dдробьsin2d+2
Илюха отвечает:
 * ctgx = (1 - (cos^{2}x - sin^{2}x)) * ctgx =%C2%A0)
(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” title=”(1-cos2x) * ctgx = (1 – (cos^{2}x – sin^{2}x)) * ctgx = (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” alt=”(1-cos2x) * ctgx = (1 – (cos^{2}x – sin^{2}x)) * ctgx = (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..)