ex2-1.mws

Spreadsheet in Maple

Use the spreadsheet in Maple to experiment with the 3x + 1 problem.

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

15 50
46 25
23 76
70 38
35 19
106 58
53 29
160 88
80 44
40 22
20 11
10 34
5 17
16 52
8 26
4 13
2 40
1 20
4 10
2 5
1 16
4 8

How is the number pattern related to the sucessive derivatives of tan(x) formed?

> restart;

>

tan(x)
1+tan(x)^2
2*tan(x)+2*tan(x)^3
2+8*tan(x)^2+6*tan(x)^4
16*tan(x)+40*tan(x)^3+24*tan(x)^5
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
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...

How is the number pattern related to the sucessive derivatives of cot(x) formed?

>

cot(x)
-1-cot(x)^2
2*cot(x)+2*cot(x)^3
-2-8*cot(x)^2-6*cot(x)^4
16*cot(x)+40*cot(x)^3+24*cot(x)^5
-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
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*cot(x)...

Express tan(nx) as a rational function of tan(x) for n = 1,2,3,4,5,6.

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)^...

Study the number pattern associated with the indefinite integral of the function

x^n e^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...

List the Chebyshev polynomials Tn(x) for n = 0,1,2,3,4,5,6.

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)