A)
var p,x,y:real;
begin
readln (x,y);
p:=(x*sin(x))/y;
writeln (p);
end.
b)
var z,x,y:real;
begin
readln (x,y);
z:=sqr(sin(x+y))/sqr(x+y);
writeln (z);
end.
c)
var z,x,y:real;
begin
readln (x,y);
z:=(x*x*x+y*y)/(y*sin(x));
writeln (z);
end.
d)
var p,x,y:real;
begin
readln (x,y);
p:=2*sin(x*x+y*y)/cos(x*x+y*y); // tg(a)=sin(a)/cos(a)
writeln (p);
end.