Question

en+un+triangulo+rectangulo+si+la+tan+de+a+es+tres+cuartos+halla+el+valor+de+csc+de+b+sabiendo+que+el+lado+bc+es+x+y+el+lado+ac+es+16+u

Answer 1

csc(b) = 1/sen(b);
sen(b) = cos(a) = 1/(sec(a)) = 1/√(1+tan²a)
Reemplazas:
tan(a) = 3/4

sen(b) = 1/√(1+9/16) = 4/5

csc(b) = 1/(4/5) = 5/4