# # # WORKSHEET#19 # # Integration in Maple # # # # -------------------------------------------------------------------------------- > f:=1/(x^2+1); 1 f := ------ 2 x + 1 -------------------------------------------------------------------------------- > int(f,x); arctan(x) -------------------------------------------------------------------------------- > diff(",x); 1 ------ 2 x + 1 -------------------------------------------------------------------------------- > Int(f,x); / | 1 | ------ dx | 2 / x + 1 -------------------------------------------------------------------------------- > Int(f,x)=int(f,x); / | 1 | ------ dx = arctan(x) | 2 / x + 1 -------------------------------------------------------------------------------- > Int(f,x)=int(f,x)+c; / | 1 | ------ dx = arctan(x) + c | 2 / x + 1 -------------------------------------------------------------------------------- > f:=1/sqrt(x^2-1); 1 f := ----------- 2 1/2 (x - 1) -------------------------------------------------------------------------------- > int(f,x); 2 1/2 ln(x + (x - 1) ) -------------------------------------------------------------------------------- > diff(",x); x 1 + ----------- 2 1/2 (x - 1) --------------- 2 1/2 x + (x - 1) -------------------------------------------------------------------------------- > simplify("); 1 ----------- 2 1/2 (x - 1) -------------------------------------------------------------------------------- > f:=sqrt(1-x^2); 2 1/2 f := (1 - x ) -------------------------------------------------------------------------------- > int(f,x); 2 1/2 1/2 x (1 - x ) + 1/2 arcsin(x) -------------------------------------------------------------------------------- > diff(",x); 2 2 1/2 x 1 1/2 (1 - x ) - 1/2 ----------- + ------------- 2 1/2 2 1/2 (1 - x ) 2 (1 - x ) -------------------------------------------------------------------------------- > simplify("); 2 1/2 I (x - 1) -------------------------------------------------------------------------------- > simplify("-f); 2 1/2 2 1/2 I (x - 1) - (1 - x ) -------------------------------------------------------------------------------- > simplify(",symbolic); 0 -------------------------------------------------------------------------------- > int(f,x=-1..1); 1/2 Pi -------------------------------------------------------------------------------- > int(f,x=1..2); 1/2 I 3 + 1/2 arcsin(2) - 1/4 Pi -------------------------------------------------------------------------------- > evalf((1/2)*arcsin(2)); .7853981635 - .6584789485 I -------------------------------------------------------------------------------- > evalf(""); 1.073571860 I -------------------------------------------------------------------------------- > evalf(Pi/4); .7853981635 -------------------------------------------------------------------------------- > subs(x=2,f); 1/2 (-3) -------------------------------------------------------------------------------- > evalf("); 1.732050808 I -------------------------------------------------------------------------------- > f:=1/sqrt(1-x^4); 1 f := ----------- 4 1/2 (1 - x ) -------------------------------------------------------------------------------- > int(f,x);\ / | 1 | ----------- dx | 4 1/2 / (1 - x ) -------------------------------------------------------------------------------- > evalf(int(f,x=0..1)); 1.311028778 -------------------------------------------------------------------------------- > evalf(Int(f,x=0..1)); 1.311028777 -------------------------------------------------------------------------------- > Digits:=20: -------------------------------------------------------------------------------- > evalf(int(f,x=0..1)); 1.3110287771460599053 -------------------------------------------------------------------------------- > evalf(Int(f,x=0..1)); 1.3110287771460599052 -------------------------------------------------------------------------------- > Digits:=10: -------------------------------------------------------------------------------- > int(f,x=0..1); 3/2 1/2 Pi 2 1/4 ----------- 2 GAMMA(3/4) -------------------------------------------------------------------------------- > evalf("); 1.311028778 -------------------------------------------------------------------------------- > Int(f,x=0..1); 1 / | 1 | ----------- dx | 4 1/2 / (1 - x ) 0 -------------------------------------------------------------------------------- > evalf("); 1.311028777 -------------------------------------------------------------------------------- > f:=(x^2+x+1)/(x^4-1);\ 2 x + x + 1 f := ---------- 4 x - 1 -------------------------------------------------------------------------------- > partialfrac("); 2 x + x + 1 partialfrac(----------) 4 x - 1 -------------------------------------------------------------------------------- > ?partialfrac Try one of the following topics: {parse, parfrac, parametric, parity, parallel, parampass, parameter, partition} -------------------------------------------------------------------------------- > parfrac(f); 2 x + x + 1 parfrac(----------) 4 x - 1 -------------------------------------------------------------------------------- > ?parfrac -------------------------------------------------------------------------------- > convert(f,parfrac,x); 3 1 x --------- - --------- - 1/2 ------ 4 (x - 1) 4 (x + 1) 2 x + 1 -------------------------------------------------------------------------------- > int(",x); 2 3/4 ln(x - 1) - 1/4 ln(x + 1) - 1/4 ln(x + 1) -------------------------------------------------------------------------------- > diff(",x); 3 1 x --------- - --------- - 1/2 ------ 4 (x - 1) 4 (x + 1) 2 x + 1 -------------------------------------------------------------------------------- > f:=1/(x^3-1); 1 f := ------ 3 x - 1 -------------------------------------------------------------------------------- > g:=int(f,x); 2 1/2 1/2 g := 1/3 ln(x - 1) - 1/6 ln(x + x + 1) - 1/3 3 arctan(1/3 (2 x + 1) 3 ) -------------------------------------------------------------------------------- > plot(g,x=1..4); -------------------------------------------------------------------------------- # ** Maple V Graphics ** -------------------------------------------------------------------------------- > limit(g,x,right); Error, (in limit) invalid arguments -------------------------------------------------------------------------------- > ?limit -------------------------------------------------------------------------------- > limit(g,x=1,right); - infinity -------------------------------------------------------------------------------- > limit(g,x=1,left); - infinity -------------------------------------------------------------------------------- > g(-2); 2 1/3 ln(x - 1)(-2) - 1/6 ln(x + x + 1)(-2) 1/2 1/2 - 1/3 3 arctan(1/3 (2 x + 1) 3 )(-2) -------------------------------------------------------------------------------- > subs(x=-2,g); 1/2 1/2 1/3 ln(-3) - 1/6 ln(3) - 1/3 3 arctan(- 3 ) -------------------------------------------------------------------------------- > evalf("); .7877018364 + 1.047197551 I -------------------------------------------------------------------------------- > ln(-3); ln(-3) -------------------------------------------------------------------------------- > evalf("); 1.098612289 + 3.141592654 I -------------------------------------------------------------------------------- > subs(x=2.0,g); 1/2 1/2 1/3 ln(1.0) - 1/6 ln(7.00) - 1/3 3 arctan(1.666666667 3 ) -------------------------------------------------------------------------------- > evalf("); -1.038687215 -------------------------------------------------------------------------------- > limit(g,x=infinity); 1/2 - 1/6 3 Pi -------------------------------------------------------------------------------- > evalf("); -.9068996827 -------------------------------------------------------------------------------- > int(f,x=0..2); 2 / | 1 | ------ dx | 3 / x - 1 0 -------------------------------------------------------------------------------- > evalf("); Error, (in evalf/int) unable to handle singularity -------------------------------------------------------------------------------- > int(f,x=0..0.9); 1/2 - 1.520747795 + 1.047197551 I + 1/18 3 Pi - 1/3 I Pi -------------------------------------------------------------------------------- > evalf("); -1.218447901 -------------------------------------------------------------------------------- > evalf(Int(f,x=0..0.9)); -1.218447901 -------------------------------------------------------------------------------- > int(f,x=2..infinity); 1/2 1/2 1/2 - 1/6 3 Pi + 1/6 ln(7) + 1/3 3 arctan(5/3 3 ) -------------------------------------------------------------------------------- > evalf("); .1317875321 -------------------------------------------------------------------------------- > g:=int(exp(-x^2),x); 1/2 g := 1/2 Pi erf(x) -------------------------------------------------------------------------------- > diff(g,x); 2 exp(- x ) -------------------------------------------------------------------------------- > subs(x=0,g); 1/2 1/2 Pi erf(0) -------------------------------------------------------------------------------- > erf(0); 0 -------------------------------------------------------------------------------- > ?erf -------------------------------------------------------------------------------- > int(exp(-x^2),x=0..infinity); 1/2 1/2 Pi > erf(infinity); 1 -------------------------------------------------------------------------------- > int((sin(x))^4,x); 3 - 1/4 sin(x) cos(x) - 3/8 cos(x) sin(x) + 3/8 x -------------------------------------------------------------------------------- > diff(",x); 2 2 4 2 2 - 3/4 sin(x) cos(x) + 1/4 sin(x) + 3/8 sin(x) - 3/8 cos(x) + 3/8 -------------------------------------------------------------------------------- > simplify("); 2 4 - 2 cos(x) + 1 + cos(x) -------------------------------------------------------------------------------- > simplify("-(sin(x))^4); 0 -------------------------------------------------------------------------------- > int(sin(x)/x,x); Si(x) > ?Si -------------------------------------------------------------------------------- > Si(0); 0 -------------------------------------------------------------------------------- > Si(infinity); 1/2 Pi -------------------------------------------------------------------------------- > Int(sin(x)/x,x=0..infinity)=Si(infinity); infinity / | sin(x) | ------ dx = 1/2 Pi | x / 0 -------------------------------------------------------------------------------- > f:='f': -------------------------------------------------------------------------------- > L(f)=Int(exp(-s*t)*f(t),t=0..infinity); infinity / | L(f) = | exp(- s t) f(t) dt | / 0 -------------------------------------------------------------------------------- > int(exp(-s*t),t=0..infinity); exp(- s t) limit - ---------- + 1/s t -> infinity- s -------------------------------------------------------------------------------- > assume(s>0); -------------------------------------------------------------------------------- > int(exp(-s*t),t=0..infinity); 1 ---- s~ -------------------------------------------------------------------------------- > about(s); Originally s, renamed s~: is assumed to be: RealRange(Open(0),infinity) -------------------------------------------------------------------------------- > Int(exp(-s*t)*t^(1/2),t=0..infinity)=int(exp(-s*t)*t^(1/2),t=0..infinity); infinity / 1/2 | 1/2 Pi | exp(- s~ t) t dt = 1/2 ----- | 3/2 / s~ 0 -------------------------------------------------------------------------------- > Int(exp(-s*t)*exp(t),t=0..infinity)=int(exp(-s*t)*exp(t),t=0..infinity); infinity / | exp(t) exp(- s~ t) 1 | exp(- s~ t) exp(t) dt = limit - ------------------ + ------ | t -> infinity- s~ - 1 s~ - 1 / 0 -------------------------------------------------------------------------------- > additionally(s>1); -------------------------------------------------------------------------------- > Int(exp(-s*t)*exp(t),t=0..infinity)=int(exp(-s*t)*exp(t),t=0..infinity); infinity / | 1 | exp(- s~ t) exp(t) dt = ------ | s~ - 1 / 0 -------------------------------------------------------------------------------- > about(s); Originally s, renamed s~: is assumed to be: RealRange(Open(1),infinity) -------------------------------------------------------------------------------- > s:='s': -------------------------------------------------------------------------------- > ?laplace -------------------------------------------------------------------------------- > laplace(1,t,s); 1/s -------------------------------------------------------------------------------- > laplace(t^(1/2),t,s);laplace(t*exp(t),t,s);laplace(exp(a*t),t,s);\ laplace(sin(b*t),t,s); 1/2 Pi 1/2 ----- 3/2 s 1 -------- 2 (s - 1) 1 ----- s - a b ------- 2 2 s + b -------------------------------------------------------------------------------- > ?invlaplace -------------------------------------------------------------------------------- > invlaplace(s/(s^2+b^2),s,t); cos(b t) -------------------------------------------------------------------------------- > invlaplace(1/(s-1)^3,s,t);invlaplace(1/sqrt(s^2+b^2),s,t);\ invlaplace(exp(-s^2),s,t); 2 1/2 t exp(t) BesselJ(0, b t) 2 invlaplace(exp(- s ), s, t) --------------------------------------------------------------------------------