Question

1)cos=1/4⇒sin; tg-?
2)sin=0.8⇒cos; tg-?

Answer 1

1) sin^2=1-1/16
sin^2=15/16
sin=sqrt(15)/4
tg=sqrt(15)/4/1/4
2)cos^2=0.36
cos=0.6
tg=0.8/0.6