Найти Ctg^2 x ,если 25sin^2 x+44cos^2 x=36

Question

Найти Ctg^2 x ,если 25sin^2 x+44cos^2 x=36

Answer 1

1+сtg^2=1/sin^2
25sin^2+44(1-sin^2)=36
25sin^2+44-44sin^2=36
8-19sin^2=0
8/sin^2-19=0
(8/sin^2-8)-11=0
8ctg^2-11=0
ctg^2=11/8