condi prob question, stuck

#1
if f(x,y)=3 from 0<x<1, 0<y<x.

whats the conditional densiity function for fy(y|x<0.3)?

i try to use bayer theorm and marginal density, but couldn't solve it.
 

BGM

TS Contributor
#2
Calculate the conditional CDF by definition of conditional probability, and then do differentiation to obtain the conditional pdf.