??????? ?????????? ??????? ( \( X, Y \) ), ??? ????????? ????????? ????????????:
\[
f_{(X, Y)}(x, y)=c\left(x^{2}+y\right),
\]
?? \( 0 \leq x \leq 1,0 \leq y \leq 2 \).
??????:
a. ???????? \( c \);
b. ????????? ?????????? \( f_{X}(x) \);
c. \( P(X \leq 0,5), P(Y \geq 1 \mid X \leq 0,5) \).