hi 

i want to plot this equations , i want to show that step by step and remind previous . i plot with animte plot but it do not show the previous

restart;
with(plottools);
co := blue;
with(plots);

t := 1;
for i from 20 by -1 to 0 do t := t+1; a[i] := -i*x/t+i; p[i] := plot(a[i], x = 0 .. 20, y = 0 .. 20, color = co, thickness = 3) end do;

plots[animate](plot, [a[k], x = 0 .. 20, y = 0 .. 20], k = [seq(i, i = 1 .. 20)]);

how can i define this  operation of diff in matrix

i want to draw a truss with graph theory 

hi

how can i write a number or word on the column or right the row of matrix as this pic

i wnat to take this export numbers from for loops in the matrix
restart;
with(LinearAlgebra);
f(x) :=  3*x^2+1 :
for i by .5 to 3.5 do print(i, f(i)) end do;

same this pic