Derivatives of Functions Maple can differentiate most elementary functions: 1. The differentiation command is diff: > diff(3*x^4 -4*x^2 -5, x); 3 12 x - 8 x > diff((x+1)^2/(x^2 +2*x)^2, x); 2 x + 1 (x + 1) (2 x + 2) 2 ----------- - 2 ------------------ 2 2 2 3 (x + 2 x) (x + 2 x) Investigating a Function Using plot and diff > f := (x+2)/(3 +(x^2 +1)^3); x + 2 f := ------------- 2 3 3 + (x + 1) > plot(f, x=-5..5); > plot(f, x=-5..5, y=-0.1..0.1); You can determine where maxima,minima, and points of inflection occur by looking at the derivatives of f(x): > f:= (x+2)/(3+(x^2 +1)^3); x + 2 f := ------------- 2 3 3 + (x + 1) > d := diff( f,x); 2 2 1 (x + 2) (x + 1) x d := ------------- - 6 ------------------- 2 3 2 3 2 3 + (x + 1) (3 + (x + 1) ) > simplify(d); 6 4 2 5 3 -4 + 5 x + 9 x + 3 x + 12 x + 24 x + 12 x - ---------------------------------------------- 6 4 2 2 (4 + x + 3 x + 3 x ) > fsolve(numer(")); -2.485165927, .2700964050 You can more clearly see the behavior of the function to the left of zero by choosing appropriate x and y values: > plot(f, x=-4..0, y=-0.01..0.01); Now for the points of inflection: > diff(d, x); 2 2 2 4 2 (x + 1) x (x + 2) (x + 1) x -12 ---------------- + 72 -------------------- 2 3 2 2 3 3 (3 + (x + 1) ) (3 + (x + 1) ) 2 2 2 2 (x + 2) (x + 1) x (x + 2) (x + 1) - 24 ------------------- - 6 ----------------- 2 3 2 2 3 2 (3 + (x + 1) ) (3 + (x + 1) ) > simplify("); 2 2 4 6 5 3 9 6 (x + 1) (-8 - 12 x - 22 x + 36 x + 40 x + 6 x - 25 x + 5 x 7 8 / 6 4 2 3 + 12 x + 14 x ) / (4 + x + 3 x + 3 x ) / > fsolve(numer(")); -2.964270928, -.5472819999, .8702050673 Integrals of Functions > int(3*x^4 -2*x,x); 5 2 3/5 x - x > int(sec(x)^4,x); sin(x) sin(x) 1/3 ------- + 2/3 ------ 3 cos(x) cos(x) Maple can perform integration by parts: > int(x^3*ln(x), x); 4 4 1/4 x ln(x) - 1/16 x > int(x^2/sqrt(x^2 -9), x); 2 1/2 2 1/2 1/2 x (x - 9) + 9/2 ln(x + (x - 9) ) > diff(", x); x 1 + ----------- 2 2 1/2 2 1/2 x (x - 9) 1/2 (x - 9) + 1/2 ----------- + 9/2 --------------- 2 1/2 2 1/2 (x - 9) x + (x - 9) > simplify("); 2 x ----------- 2 1/2 (x - 9) > int((x^2 +2*x +1)/((x^2 +1)^2*(x-2)), x); 2 13 -2 x - 4 9/25 ln(x - 2) - 9/50 ln(x + 1) - -- arctan(x) - 1/10 -------- 25 2 x + 1 You can also evaluate definite integrals: > int(sin(x), x=0..Pi/2); 1 > with(student); [D, Diff, Doubleint, Int, Limit, Lineint, Product, Sum, Tripleint, changevar, combine, completesquare, distance, equate, extrema, integrand, intercept, intparts, isolate, leftbox, leftsum, makeproc, maximize, middlebox, middlesum, midpoint, minimize, powsubs, rightbox, rightsum, showtangent, simpson, slope, trapezoid, value] > Int(x*sin(x), x); / | | x sin(x) dx | / The Int operator with a capital I creates the integral but does not evaluate it. > intparts(",x); / | intparts( | x sin(x) dx, x) | / >