Question

Найдите tg^2a, если 4sin^2a + 9cos^2a =6

Answer 1

Tg6 sin3 * 2 = cos6 : 3 = 2 ответ : 2 :D

Answer 2

Sin2(a) +cos2(a)=1
4( sin2(a) +cos2(a))=4
тогда
4sin2(a) +9cos2(a)=4 sin2(a) +4cos2(a)+ 5cos2(a)=4+5cos2(a)=6
5cos2(a) = 2

tg2(a) = 1 - 1/ cos2(a) = 1- 1/(2/5)=1-5/2=-3/2