Cos^2t - sin^2t/tg (-2) ctg2

Question

Алгебра

Тоша

6 января, 17:52

Cos^2t - sin^2t/tg (-2) ctg2

+1

Ответы (2)

Знаете ответ на вопрос?

Ангелиныч · Answer 1

(cost) ^2 - (sint) ^2/tg (-2) * ctg2 = (cost) ^2 - (sint) ^2 / (-1) = (cost) ^2 + (sint) ^2=1

tg (-2) * ctg (2) = - tg (2) * ctg (2) = - 1

Себастьян · Answer 2

Sin^2 (t) * cos^2 (t) * [ (sin^2 (t) / cos^2 (t)) + (cos^2 (t) / sin^2 (t)) + 2) ]=

=sin^2 (t) * cos^2 (t) * [ (sin^4 (t) + cos^4 (t) + 2cos^2 (t) * sin^2 (t)) / sin^2 (t) * cos^2 (t) ]=

= (cos^2 (t) + sin^2 (t)) ^2=1