granny23
Я вместо α буду писать а(чтобы быстрей) (1-cos a)/(1+ sin a) + (1+cos a)/(1-sin a) = = (1-cos a)(1-sin a)+(1+cos a)(1+sin a) / (1+sin a)(1-sin a) = = (1-cos a-sin a+cos a*sin a+1+cos a+sin a+cos a*sin a)/(1-sin^2 a)= (2+2sin a*cos a)/cos^2 a = 2(1+sin a*cos a)/cos^2 a = 2*(1/cos^2 a +tg a)= 2*(tg^2 a+1+tg a)= 2(1+tg a+tg^2 a) - чтд
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Решение во вложении----------------------------(1-cos a)/(1+ sin a) + (1+cos a)/(1-sin a) =
= (1-cos a)(1-sin a)+(1+cos a)(1+sin a) / (1+sin a)(1-sin a) =
= (1-cos a-sin a+cos a*sin a+1+cos a+sin a+cos a*sin a)/(1-sin^2 a)=
(2+2sin a*cos a)/cos^2 a = 2(1+sin a*cos a)/cos^2 a = 2*(1/cos^2 a +tg a)=
2*(tg^2 a+1+tg a)= 2(1+tg a+tg^2 a) - чтд