alumi021.mws

1. 3x + 1 problem.

2.將 tan(x) 連續微分的數學圖案

3.將 cot(x) 連續微分的數學圖案

> f:=x->if x mod 2 =0 then x/2 else 3*x+1 fi;

f := proc (x) options operator, arrow; if `mod`(x,2...

> f(20);

10

> f(31);

94

>

10 37 27 tan(x) cot(x) u v
5 112 82 1+tan(x)^2 -1-cot(x)^2 1+u^2 -1-v^2
16 56 41 2*tan(x)+2*tan(x)^3 2*cot(x)+2*cot(x)^3 2*u+2*u^3 2*v+2*v^3
8 28 124 2+8*tan(x)^2+6*tan(x)^4 -2-8*cot(x)^2-6*cot(x)^4 2+8*u^2+6*u^4 -2-8*v^2-6*v^4
4 14 62 16*tan(x)+40*tan(x)^3+24*tan(x)^5 16*cot(x)+40*cot(x)^3+24*cot(x)^5 16*u+40*u^3+24*u^5 16*v+40*v^3+24*v^5
2 7 31 16+136*tan(x)^2+240*tan(x)^4+120*tan(x)^6
16+136*tan(x)^2+240*tan(x)^4+120*tan(x)^6
-16-136*cot(x)^2-240*cot(x)^4-120*cot(x)^6
-16-136*cot(x)^2-240*cot(x)^4-120*cot(x)^6
16+136*u^2+240*u^4+120*u^6 -16-136*v^2-240*v^4-120*v^6
1 22 94 272*tan(x)+1232*tan(x)^3+1680*tan(x)^5+720*tan(x)^7...
272*tan(x)+1232*tan(x)^3+1680*tan(x)^5+720*tan(x)^7...
272*cot(x)+1232*cot(x)^3+1680*cot(x)^5+720*cot(x)^7...
272*cot(x)+1232*cot(x)^3+1680*cot(x)^5+720*cot(x)^7...
272*u+1232*u^3+1680*u^5+720*u^7 272*v+1232*v^3+1680*v^5+720*v^7
4 11 47



2 34 142



1 17 71



4 52 214



2 26 107



1 13 322



4 40 161



2 20 484



1 10 242



4 5 121



2 16 364



1 8 182



4 4 91



2 2 274



1 1 137



4 4 412



2 2 206



1 1 103



4 4 310



2 2 155



1 1 466



4 4 233



2 2 700



4.將 tan(nx) 表示成tan(x)的有理函數 (n=1 to 6)

> expand(tan(2*x));

2*tan(x)/(1-tan(x)^2)

> expand(tan(3*x));

(3*tan(x)-tan(x)^3)/(1-3*tan(x)^2)

> expand(tan(4*x));

(4*tan(x)-4*tan(x)^3)/(1-6*tan(x)^2+tan(x)^4)

> expand(tan(5*x));

(5*tan(x)-10*tan(x)^3+tan(x)^5)/(1-10*tan(x)^2+5*ta...

> expand(tan(6*x));

(6*tan(x)-20*tan(x)^3+6*tan(x)^5)/(1-15*tan(x)^2+15...

>

tan(x) tan(x)
tan(2*x) -2*tan(x)/(-1+tan(x)^2)
tan(3*x) tan(x)*(-3+tan(x)^2)/(-1+3*tan(x)^2)
tan(4*x) -4*tan(x)*(-1+tan(x)^2)/(1-6*tan(x)^2+tan(x)^4)
tan(5*x) tan(x)*(5-10*tan(x)^2+tan(x)^4)/(1-10*tan(x)^2+5*ta...
tan(6*x) -2*tan(x)*(3-10*tan(x)^2+3*tan(x)^4)/(-1+15*tan(x)^...
-2*tan(x)*(3-10*tan(x)^2+3*tan(x)^4)/(-1+15*tan(x)^...

5.將 x^n*exp(x) 不定積分 (n=1,2,3............)

> int(x*exp(x),x);

>

x*exp(x)-exp(x)

> int(x^2*exp(x),x);

x^2*exp(x)-2*x*exp(x)+2*exp(x)

> int(x^3*exp(x),x);

x^3*exp(x)-3*x^2*exp(x)+6*x*exp(x)-6*exp(x)

> f:=n->x^n*exp(x);

f := proc (n) options operator, arrow; x^n*exp(x) e...

> int(x^4*exp(x),x);

x^4*exp(x)-4*x^3*exp(x)+12*x^2*exp(x)-24*x*exp(x)+2...

> int(x^5*exp(x),x);

x^5*exp(x)-5*x^4*exp(x)+20*x^3*exp(x)-60*x^2*exp(x)...

> int(x^6*exp(x),x);

x^6*exp(x)-6*x^5*exp(x)+30*x^4*exp(x)-120*x^3*exp(x...

> int(x^7*exp(x),x);

x^7*exp(x)-7*x^6*exp(x)+42*x^5*exp(x)-210*x^4*exp(x...

>

1 x*exp(x)-exp(x)
2 x^2*exp(x)-2*x*exp(x)+2*exp(x)
3 x^3*exp(x)-3*x^2*exp(x)+6*x*exp(x)-6*exp(x)
4 x^4*exp(x)-4*x^3*exp(x)+12*x^2*exp(x)-24*x*exp(x)+2...
x^4*exp(x)-4*x^3*exp(x)+12*x^2*exp(x)-24*x*exp(x)+2...
5 x^5*exp(x)-5*x^4*exp(x)+20*x^3*exp(x)-60*x^2*exp(x)...
x^5*exp(x)-5*x^4*exp(x)+20*x^3*exp(x)-60*x^2*exp(x)...
6 x^6*exp(x)-6*x^5*exp(x)+30*x^4*exp(x)-120*x^3*exp(x...
x^6*exp(x)-6*x^5*exp(x)+30*x^4*exp(x)-120*x^3*exp(x...
7 x^7*exp(x)-7*x^6*exp(x)+42*x^5*exp(x)-210*x^4*exp(x...
x^7*exp(x)-7*x^6*exp(x)+42*x^5*exp(x)-210*x^4*exp(x...
x^7*exp(x)-7*x^6*exp(x)+42*x^5*exp(x)-210*x^4*exp(x...

>

6.列出 Chebyshev polynomials Tn(x) (n=1 to 6)

cos(x) cos(x)
cos(2*x) 2*cos(x)^2-1
cos(3*x) 4*cos(x)^3-3*cos(x)
cos(4*x) 8*cos(x)^4-8*cos(x)^2+1
cos(5*x) 16*cos(x)^5-20*cos(x)^3+5*cos(x)
cos(6*x) 32*cos(x)^6-48*cos(x)^4+18*cos(x)^2-1
cos(7*x) 64*cos(x)^7-112*cos(x)^5+56*cos(x)^3-7*cos(x)
64*cos(x)^7-112*cos(x)^5+56*cos(x)^3-7*cos(x)