COALITION MATH 151, FALL 1997 Group II (S. A. Fulling, assisted by Cary Lasher) Day 4.2 1. Antiderivatives, velocity, and acceleration. A. Speedometer-odometer paradigm. B. Activity: Polynomial example. State problem in mathematical and then in physical terms. Emphasize that at^2/2 + ... applies only to CONSTANT acceleration. C. State formulas for derivatives of sine and cosine. D. Activity: Problems with cosine as antiderivative. State problem in mathematical and then in physical terms. Emphasize that the constant of integration is not always the initial value. E. Mention that e^{-x^2} and (sin x)/x do not have elementary antiderivatives. THIS WENT WELL, BUT CONSUMED THE ENTIRE PERIOD. (TIME AT BEGINNING HAD TO BE SPENT RESOLVING CAPA TROUBLES.) THE EMPHASIZED ERRORS DID NOT APPEAR IN EITHER MATHEMATICAL OR PHYSICAL FORMULATION (UNLIKE LAST YEAR'S TESTS). BOTH TEAMS DOING THE INITIAL MATHEMATICAL PROBLEMS HAD SURPRISING TECHNICAL DIFFICULTY, BUT MOST OTHER TEAMS SEEMED QUITE COMPETENT. POSTPONED THE FOLLOWING TO NEXT DAY. 2. Derivatives and antiderivatives in Maple. A. Explore D, diff, unapply, Limit, value, D@@2. B. Explore int, Int, value. (Cf. 1E.) C. Direction fields: with(DEtools); dfieldplot(diff(y(x),x)=, y(x), -1..3, y=-1..4); (These ranges are good for sqrt(1+x^3) - x, corresponding to Stewart ed. 3 p. 247, Fig. 4.) SUCCESSFUL, FOLLOWING THIS SCRIPT: > f := 3^x; > D(f); > diff(f); > diff(f,x); > g:=unapply(f,x); > h:= x-> 3^x; > i:=unapply(3^x,x); > D(g); > Limit( (g(x+h) - g(x))/h, h=0); > value("); > Delta_f := subs(x=x+h, f) - f; > D@@2(h); > (D@@2)(h); > Int(x^2, x); > value("); > int(x^2, x); > (D@@(-1))(g); > int(f,x); > int(g,x); > int(g(x), x); > k := unapply(", x); > Int(exp(-x^2), x); > value("); > Int(sin(x)/x, x); > value("); > help(Si); > help(erf); > plot(erf); > plot(Si); > with(DEtools); > dfieldplot( diff(y(x),x) = x, y(x), -10..10, y=-10..10); > dfieldplot(diff(y(x),x) = sqrt(1+x^3) -x, y(x), -1..3, y=-1..4); #Stewart p. 257 Fig. 4 > dfieldplot(diff(y(x),x) = exp(-x^2), y(x), -2..2, y= -2..2); >