Здравствуйте, JonMoxley!

Смотрите приложение:
[code lang=pascal]type
f=function(a:real):real;
{$F+}
function f2(a:real):real;
begin
f2:=a*a
end;
function fe(a:real):real;
begin
fe:=exp(a)
end;
function fs(a:real):real;
begin
fs:=(exp(a)-exp(a))/2
end;
{$F-}
function fmin(a,b:real):real;
begin
if a>b then fmin:=b
else fmin:=a
end;
var
a:integer;
b:f;
x,y,z:real;
begin
write('Enter X:=');readln(x);
write('Enter Y:=');readln(y);
write('Enter Z:=');readln(z);
repeat
write('select function:',#10,#13,'1-x^2',#10,#13,'2-sh(x)',#10,#13,'3-e^x');
readln(a);
until a in[1..3];
case a of
1:b:=f2;
2:b:=fs;
3:b:=fe;
end;
if fmin(b(x),y)<>0then writeln('Result:=',fmin(b(x)+y,y-z)/fmin(b(x),y))
else writeln('Result - undefined')
end.[/code]
Удачи!