Question

Если ctga=15/8, тогда tga, cosa, sina=? Помогиите

Answer 1

tga=1/ctga=8/15 cosa/sina=15/8
1+tg^2a=1/cos^2a
1+64/225=1/cos^2a
1 64/225=1/cos^2a^
289/225=1/cos^2a
1/cosa=17/15
cosa=15/17
sin^2a=1-225/289
sina=8/17