| > | myeq:=y=3*x+7; |
|
(1) |
| > | solve(myeq,{x}); |
 |
(2) |
| > | solve(y=3*x+7,{x}); |
 |
(3) |
| > |
| > |
| > | with(DEtools): |
| > | R:='R';
phug:= [ diff(theta(t),t) = ( v(t)^2 - cos(theta(t))) / v(t), diff(v(t),t) = -sin(theta(t)) - R*v(t)^2 ]; |
 |
|
![[diff(theta(t), t) = `/`(`*`(`+`(`*`(`^`(v(t), 2)), `-`(cos(theta(t))))), `*`(v(t))), diff(v(t), t) = `+`(`-`(sin(theta(t))), `-`(`*`(R, `*`(`^`(v(t), 2)))))]](images/08-03-06_5.gif){kind=small} |
(4) |
| > | R:=0;DEplot( phug, [ theta(t), v(t) ], t=0..6, |
| > | [seq([theta(0)=0, v(0)=0.5+2*i/10], i=0..10)], |
| > | theta=-Pi/2..2*Pi, v=0..3, |
| > | linecolor=[seq(COLOR(HUE, i/10), i=0..10)]); |
| > |
| > |
 |
|
 |
| > | R:=0;DEplot( phug, [ theta(t), v(t) ], t=0..6, |
| > | [seq([theta(0)=0, v(0)=0.5+2*i/10], i=0..10)], |
| > | theta=-Pi/2..2*Pi, v=0..3, |
| > | linecolor=[seq(COLOR(HUE, i/10), i=0..10)], method=classical[foreuler],
stepsize=1); |
| > |
| > |
 |
|
 |
| > | DEplot( phug, [ theta(t), v(t) ], t=0..6, |
| > | [seq([theta(0)=0, v(0)=0.5+2*i/10], i=0..10)], |
| > | theta=-Pi/2..2*Pi, v=0..3, |
| > | linecolor=[seq(COLOR(HUE, i/10), i=0..10)], method=classical[foreuler],
stepsize=.1); |
| > |
 |
| > | DEplot( phug, [ theta(t), v(t) ], t=0..6, |
| > | [seq([theta(0)=0, v(0)=0.5+2*i/10], i=0..10)], |
| > | theta=-Pi/2..2*Pi, v=0..3, |
| > | linecolor=[seq(COLOR(HUE, i/10), i=0..10)], method=classical[rk4],
stepsize=.1); |
| > |
 |
| > | R:=0.1; |
| > | DEplot( phug, [ theta(t), v(t) ], t=0..6, |
| > | [seq([theta(0)=0, v(0)=0.5+2*i/10], i=0..10)], |
| > | theta=-Pi/2..4*Pi, v=0..3, |
| > | linecolor=[seq(COLOR(HUE, i/10), i=0..10)], method=classical[rk4],
stepsize=.1); |
| > |
 |
|
 |
| > | DEplot( phug, [ theta(t), v(t) ], t=0..20, |
| > | [[theta(0)=0,v(0)=2]], |
| > | theta=-Pi/2..8, v=0..3, |
| > | linecolor=[seq(COLOR(HUE, i/10), i=0..10)], method=classical[rk4],
stepsize=.01); |
| > |
 |
| > |
| > |