Contributor: LOU DUCHEZ { LOU DUCHEZ } program mathtest; uses calculus; var answer : real; {$F+} { WARNING! YOU NEED "FAR" FUNCTIONS! } function y(x : real) : real; begin y := 2 * sqrt(4 - x * x); end; {$F-} begin Writeln; Writeln('Function: y = 2 * (4 - x^2)^(1/2) (i.e., Circle Radius 2)'); Writeln; { Calc operations here are: } { Integrate function from -2 to 2, in increments of 0.001. A half circle. } { However since equation multiplies it by 2, then we get area of full circle } { Get slope of function at 0 by evaluating points 0.01 away from each other. } { Find extremum of function, starting at 0.4, initially looking at points 0.1 on either side of 0.4, and not stopping until we have two x-values within 0.001 of each other. } answer := integral(-2, 2, 0.001, @y); writeln('Integ: ', answer:13:9); answer := derivative(1, 0.001, @y); writeln('Deriv: ', answer:13:9); answer := extremum(0.4, 0.1, 0.001, @y); writeln('Extrm: ', answer:13:9); Writeln(4*Pi:0:6); end.