Can't plot DSolve's solution to Riccati differential equation
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DSolve gives a strange solution for the Riccati differential equation $ y' = (y^2) - 2 x^2 y + (x^4) + 2 x + 4 $
Opres = DSolve[y'[x] == y[x]^2-2x^2*y[x]+x^4+2x+4, y[x], x]
$left{left{y(x)to frac{1}{c_1 e^{4 i x}-frac{i}{4}}+x^2-2 iright}right}$
When I try plot this solution
Opresgraf =
Plot[Evaluate[y[x] /. Opres /. C[1] -> Range[-3, 3]], {x, -4.7, 4.7},
PlotRange -> 4.7]
I get a blank graph.
My question is: how can I get a solution with DSolve
(not with NDSolve
, because in my student research project I need DSolve
) and plot that solution, the most important is to plot that general solution with DSolve
.
differential-equations
add a comment |
up vote
2
down vote
favorite
DSolve gives a strange solution for the Riccati differential equation $ y' = (y^2) - 2 x^2 y + (x^4) + 2 x + 4 $
Opres = DSolve[y'[x] == y[x]^2-2x^2*y[x]+x^4+2x+4, y[x], x]
$left{left{y(x)to frac{1}{c_1 e^{4 i x}-frac{i}{4}}+x^2-2 iright}right}$
When I try plot this solution
Opresgraf =
Plot[Evaluate[y[x] /. Opres /. C[1] -> Range[-3, 3]], {x, -4.7, 4.7},
PlotRange -> 4.7]
I get a blank graph.
My question is: how can I get a solution with DSolve
(not with NDSolve
, because in my student research project I need DSolve
) and plot that solution, the most important is to plot that general solution with DSolve
.
differential-equations
1
You can't plot a complex expression. You need to either plot its real value, its imaginary value or its modulus. Also you have a typo in the input, you needy[x]
noty
in the ODE itself.
– Nasser
4 hours ago
1
IsRange[-3.3]
supposed to beRange[-3,3]
?
– That Gravity Guy
4 hours ago
add a comment |
up vote
2
down vote
favorite
up vote
2
down vote
favorite
DSolve gives a strange solution for the Riccati differential equation $ y' = (y^2) - 2 x^2 y + (x^4) + 2 x + 4 $
Opres = DSolve[y'[x] == y[x]^2-2x^2*y[x]+x^4+2x+4, y[x], x]
$left{left{y(x)to frac{1}{c_1 e^{4 i x}-frac{i}{4}}+x^2-2 iright}right}$
When I try plot this solution
Opresgraf =
Plot[Evaluate[y[x] /. Opres /. C[1] -> Range[-3, 3]], {x, -4.7, 4.7},
PlotRange -> 4.7]
I get a blank graph.
My question is: how can I get a solution with DSolve
(not with NDSolve
, because in my student research project I need DSolve
) and plot that solution, the most important is to plot that general solution with DSolve
.
differential-equations
DSolve gives a strange solution for the Riccati differential equation $ y' = (y^2) - 2 x^2 y + (x^4) + 2 x + 4 $
Opres = DSolve[y'[x] == y[x]^2-2x^2*y[x]+x^4+2x+4, y[x], x]
$left{left{y(x)to frac{1}{c_1 e^{4 i x}-frac{i}{4}}+x^2-2 iright}right}$
When I try plot this solution
Opresgraf =
Plot[Evaluate[y[x] /. Opres /. C[1] -> Range[-3, 3]], {x, -4.7, 4.7},
PlotRange -> 4.7]
I get a blank graph.
My question is: how can I get a solution with DSolve
(not with NDSolve
, because in my student research project I need DSolve
) and plot that solution, the most important is to plot that general solution with DSolve
.
differential-equations
differential-equations
edited 7 mins ago
kglr
173k8194400
173k8194400
asked 4 hours ago
Милош Вучковић
415
415
1
You can't plot a complex expression. You need to either plot its real value, its imaginary value or its modulus. Also you have a typo in the input, you needy[x]
noty
in the ODE itself.
– Nasser
4 hours ago
1
IsRange[-3.3]
supposed to beRange[-3,3]
?
– That Gravity Guy
4 hours ago
add a comment |
1
You can't plot a complex expression. You need to either plot its real value, its imaginary value or its modulus. Also you have a typo in the input, you needy[x]
noty
in the ODE itself.
– Nasser
4 hours ago
1
IsRange[-3.3]
supposed to beRange[-3,3]
?
– That Gravity Guy
4 hours ago
1
1
You can't plot a complex expression. You need to either plot its real value, its imaginary value or its modulus. Also you have a typo in the input, you need
y[x]
not y
in the ODE itself.– Nasser
4 hours ago
You can't plot a complex expression. You need to either plot its real value, its imaginary value or its modulus. Also you have a typo in the input, you need
y[x]
not y
in the ODE itself.– Nasser
4 hours ago
1
1
Is
Range[-3.3]
supposed to be Range[-3,3]
?– That Gravity Guy
4 hours ago
Is
Range[-3.3]
supposed to be Range[-3,3]
?– That Gravity Guy
4 hours ago
add a comment |
3 Answers
3
active
oldest
votes
up vote
5
down vote
perhaps
Plot[Evaluate[ReIm@y[x] /. (Opres /. C[1] -> Range[-3, 3])], {x, -4.7, 4.7},
PlotRange -> 4.7]
add a comment |
up vote
2
down vote
Try this
Opres = DSolve[y'[x] == y[x]^2-2x^2 *y[x]+x^4+2x+4, y[x], x][[1]];
Plot[{Re[y[x]/.Opres/.C[1]->Range[3.3]],Im[y[x]/.Opres/.C[1]->Range[3.3]]}, {x,-4.7,4.7}]
add a comment |
up vote
2
down vote
With a single graph you can only plot those solution that are imaginary or real.
There are 2 real ones:
sol = First[DSolve[y'[x] == y[x]^2 - 2 x^2*y[x] + x^4 + 2 x + 4, y[x], x]];
zeroIm = FullSimplify[ComplexExpand[Im[y[x] /. sol]]] == 0 // Solve[#, C[1]] &
$left{left{C[1]to -frac{1}{4}right},left{C[1]to frac{1}{4}right}right}$
Plot[Evaluate[y[x] /. sol /. zeroIm], {x, -4.7, 4.7}]
add a comment |
3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
5
down vote
perhaps
Plot[Evaluate[ReIm@y[x] /. (Opres /. C[1] -> Range[-3, 3])], {x, -4.7, 4.7},
PlotRange -> 4.7]
add a comment |
up vote
5
down vote
perhaps
Plot[Evaluate[ReIm@y[x] /. (Opres /. C[1] -> Range[-3, 3])], {x, -4.7, 4.7},
PlotRange -> 4.7]
add a comment |
up vote
5
down vote
up vote
5
down vote
perhaps
Plot[Evaluate[ReIm@y[x] /. (Opres /. C[1] -> Range[-3, 3])], {x, -4.7, 4.7},
PlotRange -> 4.7]
perhaps
Plot[Evaluate[ReIm@y[x] /. (Opres /. C[1] -> Range[-3, 3])], {x, -4.7, 4.7},
PlotRange -> 4.7]
answered 4 hours ago
kglr
173k8194400
173k8194400
add a comment |
add a comment |
up vote
2
down vote
Try this
Opres = DSolve[y'[x] == y[x]^2-2x^2 *y[x]+x^4+2x+4, y[x], x][[1]];
Plot[{Re[y[x]/.Opres/.C[1]->Range[3.3]],Im[y[x]/.Opres/.C[1]->Range[3.3]]}, {x,-4.7,4.7}]
add a comment |
up vote
2
down vote
Try this
Opres = DSolve[y'[x] == y[x]^2-2x^2 *y[x]+x^4+2x+4, y[x], x][[1]];
Plot[{Re[y[x]/.Opres/.C[1]->Range[3.3]],Im[y[x]/.Opres/.C[1]->Range[3.3]]}, {x,-4.7,4.7}]
add a comment |
up vote
2
down vote
up vote
2
down vote
Try this
Opres = DSolve[y'[x] == y[x]^2-2x^2 *y[x]+x^4+2x+4, y[x], x][[1]];
Plot[{Re[y[x]/.Opres/.C[1]->Range[3.3]],Im[y[x]/.Opres/.C[1]->Range[3.3]]}, {x,-4.7,4.7}]
Try this
Opres = DSolve[y'[x] == y[x]^2-2x^2 *y[x]+x^4+2x+4, y[x], x][[1]];
Plot[{Re[y[x]/.Opres/.C[1]->Range[3.3]],Im[y[x]/.Opres/.C[1]->Range[3.3]]}, {x,-4.7,4.7}]
answered 4 hours ago
Bill
5,41059
5,41059
add a comment |
add a comment |
up vote
2
down vote
With a single graph you can only plot those solution that are imaginary or real.
There are 2 real ones:
sol = First[DSolve[y'[x] == y[x]^2 - 2 x^2*y[x] + x^4 + 2 x + 4, y[x], x]];
zeroIm = FullSimplify[ComplexExpand[Im[y[x] /. sol]]] == 0 // Solve[#, C[1]] &
$left{left{C[1]to -frac{1}{4}right},left{C[1]to frac{1}{4}right}right}$
Plot[Evaluate[y[x] /. sol /. zeroIm], {x, -4.7, 4.7}]
add a comment |
up vote
2
down vote
With a single graph you can only plot those solution that are imaginary or real.
There are 2 real ones:
sol = First[DSolve[y'[x] == y[x]^2 - 2 x^2*y[x] + x^4 + 2 x + 4, y[x], x]];
zeroIm = FullSimplify[ComplexExpand[Im[y[x] /. sol]]] == 0 // Solve[#, C[1]] &
$left{left{C[1]to -frac{1}{4}right},left{C[1]to frac{1}{4}right}right}$
Plot[Evaluate[y[x] /. sol /. zeroIm], {x, -4.7, 4.7}]
add a comment |
up vote
2
down vote
up vote
2
down vote
With a single graph you can only plot those solution that are imaginary or real.
There are 2 real ones:
sol = First[DSolve[y'[x] == y[x]^2 - 2 x^2*y[x] + x^4 + 2 x + 4, y[x], x]];
zeroIm = FullSimplify[ComplexExpand[Im[y[x] /. sol]]] == 0 // Solve[#, C[1]] &
$left{left{C[1]to -frac{1}{4}right},left{C[1]to frac{1}{4}right}right}$
Plot[Evaluate[y[x] /. sol /. zeroIm], {x, -4.7, 4.7}]
With a single graph you can only plot those solution that are imaginary or real.
There are 2 real ones:
sol = First[DSolve[y'[x] == y[x]^2 - 2 x^2*y[x] + x^4 + 2 x + 4, y[x], x]];
zeroIm = FullSimplify[ComplexExpand[Im[y[x] /. sol]]] == 0 // Solve[#, C[1]] &
$left{left{C[1]to -frac{1}{4}right},left{C[1]to frac{1}{4}right}right}$
Plot[Evaluate[y[x] /. sol /. zeroIm], {x, -4.7, 4.7}]
edited 3 hours ago
answered 4 hours ago
Coolwater
14.3k32452
14.3k32452
add a comment |
add a comment |
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You can't plot a complex expression. You need to either plot its real value, its imaginary value or its modulus. Also you have a typo in the input, you need
y[x]
noty
in the ODE itself.– Nasser
4 hours ago
1
Is
Range[-3.3]
supposed to beRange[-3,3]
?– That Gravity Guy
4 hours ago