ctgα = -1 (1+ 3sinα·cosα) / (1 - 3cos²α) = ?

Question

ctgα = -1

(1+ 3sinα·cosα) / (1 - 3cos²α) = ?

Answer 1

ctga=-1

ctga=cosa/sina 

 

cosa=-sina

Ставим

 

(1-3sin^2a)/(1-3sin^2a)=1 

Ответ  1