1) sina=3/5 cosa=sqrt(1-sin^2(a))=sqrt(1-9/25)=4/5 tga=sina/cosa=(3/5)/(4/5)=3/4 ctga=1/tga=4/3
2)tg^2a + ctg^2a =(tga-ctga)^2 + 2 tg2a*ctg2a=9+2=11
1) sina=3/5 cosa=sqrt(1-sin^2(a))=sqrt(1-9/25)=4/5 tga=sina/cosa=(3/5)/(4/5)=3/4 ctga=1/tga=4/3
2)tg^2a + ctg^2a =(tga-ctga)^2 + 2 tg2a*ctg2a=9+2=11