#### 8.1.2 1.2

8.1.2.1 [2005] Problem 1
8.1.2.2 [2006] Problem 2
8.1.2.3 [2007] Problem 3
8.1.2.4 [2008] Problem 4
8.1.2.5 [2009] Problem 5

##### 8.1.2.1 [2005] Problem 1

problem number 2005

Problem Chapter 1.1.2.1, from Handbook of nonlinear partial diﬀerential equations by Andrei D. Polyanin, Valentin F. Zaitsev.

Solve for $$w(x,t)$$

$w_t = a w_{xx} - b w^3$

Mathematica

Failed

Maple

sol=()

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##### 8.1.2.2 [2006] Problem 2

problem number 2006

Problem Chapter 1.1.2.2, from Handbook of nonlinear partial diﬀerential equations by Andrei D. Polyanin, Valentin F. Zaitsev.

Solve for $$w(x,t)$$ $w_t = w_{xx} + a w - b w^3$

Mathematica

Failed

Maple

$w \left (x , t\right ) = \frac {\sqrt {a b}\, \left (\tanh \left (-\frac {3 a t}{4}+\frac {\sqrt {2}\, \sqrt {a}\, x}{4}+c_{1}\right )-1\right )}{2 b}$

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##### 8.1.2.3 [2007] Problem 3

problem number 2007

Problem Chapter 1.1.2.3, from Handbook of nonlinear partial diﬀerential equations by Andrei D. Polyanin, Valentin F. Zaitsev.

Solve for $$w(x,t)$$ $w_t = a w_{xx} - b w^3 - c w^2$

Mathematica

Failed

Maple

$w \left (x , t\right ) = \frac {\left (\tanh \left (-\frac {c^{2} t}{4 b}+\frac {\sqrt {2}\, c x}{4 \sqrt {a b}}+c_{1}\right )-1\right ) c}{2 b}$

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##### 8.1.2.4 [2008] Problem 4

problem number 2008

Problem Chapter 1.1.2.4, from Handbook of nonlinear partial diﬀerential equations by Andrei D. Polyanin, Valentin F. Zaitsev.

Solve for $$w(x,t)$$ $w_t = w_{xx} -w(1-w)(a-w)$

Mathematica

Failed

Maple

$w \left (x , t\right ) = \frac {\tanh \left (c_{1}+\frac {\left (-2 a +1\right ) t}{4}+\frac {\sqrt {2}\, x}{4}\right )}{2}+\frac {1}{2}$

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##### 8.1.2.5 [2009] Problem 5

problem number 2009

Problem Chapter 1.1.2.5, from Handbook of nonlinear partial diﬀerential equations by Andrei D. Polyanin, Valentin F. Zaitsev.

Solve for $$w(x,t)$$ $w_t = a w_{xx} +b_0+b_1 w+ b_2 w^2+ b_3 w^3$

Mathematica

Failed

Maple

$w \left (x , t\right ) = \frac {-2304 \left (a \mathit {b3} \RootOf \left (512 \textit {\_Z}^{6} a^{3} \mathit {b3}^{2}-27 \mathit {b0}^{2} \mathit {b3}^{3}+18 \mathit {b0} \mathit {b1} \mathit {b2} \,\mathit {b3}^{2}-4 \mathit {b0} \,\mathit {b2}^{3} \mathit {b3} -4 \mathit {b1}^{3} \mathit {b3}^{2}+\mathit {b1}^{2} \mathit {b2}^{2} \mathit {b3} +\left (-384 a^{2} \mathit {b1} \,\mathit {b3}^{2}+128 a^{2} \mathit {b2}^{2} \mathit {b3} \right ) \textit {\_Z}^{4}+\left (72 a \,\mathit {b1}^{2} \mathit {b3}^{2}-48 a \mathit {b1} \,\mathit {b2}^{2} \mathit {b3} +8 a \,\mathit {b2}^{4}\right ) \textit {\_Z}^{2}\right )^{2}-\frac {\mathit {b1} \mathit {b3}}{8}+\frac {\mathit {b2}^{2}}{24}\right )^{2} \RootOf \left (12 a^{2} \mathit {b3} \RootOf \left (512 \textit {\_Z}^{6} a^{3} \mathit {b3}^{2}-27 \mathit {b0}^{2} \mathit {b3}^{3}+18 \mathit {b0} \mathit {b1} \mathit {b2} \,\mathit {b3}^{2}-4 \mathit {b0} \,\mathit {b2}^{3} \mathit {b3} -4 \mathit {b1}^{3} \mathit {b3}^{2}+\mathit {b1}^{2} \mathit {b2}^{2} \mathit {b3} +\left (-384 a^{2} \mathit {b1} \,\mathit {b3}^{2}+128 a^{2} \mathit {b2}^{2} \mathit {b3} \right ) \textit {\_Z}^{4}+\left (72 a \,\mathit {b1}^{2} \mathit {b3}^{2}-48 a \mathit {b1} \,\mathit {b2}^{2} \mathit {b3} +8 a \,\mathit {b2}^{4}\right ) \textit {\_Z}^{2}\right )^{4}-6 a \mathit {b1} \mathit {b3} \RootOf \left (512 \textit {\_Z}^{6} a^{3} \mathit {b3}^{2}-27 \mathit {b0}^{2} \mathit {b3}^{3}+18 \mathit {b0} \mathit {b1} \mathit {b2} \,\mathit {b3}^{2}-4 \mathit {b0} \,\mathit {b2}^{3} \mathit {b3} -4 \mathit {b1}^{3} \mathit {b3}^{2}+\mathit {b1}^{2} \mathit {b2}^{2} \mathit {b3} +\left (-384 a^{2} \mathit {b1} \,\mathit {b3}^{2}+128 a^{2} \mathit {b2}^{2} \mathit {b3} \right ) \textit {\_Z}^{4}+\left (72 a \,\mathit {b1}^{2} \mathit {b3}^{2}-48 a \mathit {b1} \,\mathit {b2}^{2} \mathit {b3} +8 a \,\mathit {b2}^{4}\right ) \textit {\_Z}^{2}\right )^{2}+2 a \,\mathit {b2}^{2} \RootOf \left (512 \textit {\_Z}^{6} a^{3} \mathit {b3}^{2}-27 \mathit {b0}^{2} \mathit {b3}^{3}+18 \mathit {b0} \mathit {b1} \mathit {b2} \,\mathit {b3}^{2}-4 \mathit {b0} \,\mathit {b2}^{3} \mathit {b3} -4 \mathit {b1}^{3} \mathit {b3}^{2}+\mathit {b1}^{2} \mathit {b2}^{2} \mathit {b3} +\left (-384 a^{2} \mathit {b1} \,\mathit {b3}^{2}+128 a^{2} \mathit {b2}^{2} \mathit {b3} \right ) \textit {\_Z}^{4}+\left (72 a \,\mathit {b1}^{2} \mathit {b3}^{2}-48 a \mathit {b1} \,\mathit {b2}^{2} \mathit {b3} +8 a \,\mathit {b2}^{4}\right ) \textit {\_Z}^{2}\right )^{2}+\textit {\_Z}^{2} \mathit {b3} \right ) \tanh \left (t \RootOf \left (12 a^{2} \mathit {b3} \RootOf \left (512 \textit {\_Z}^{6} a^{3} \mathit {b3}^{2}-27 \mathit {b0}^{2} \mathit {b3}^{3}+18 \mathit {b0} \mathit {b1} \mathit {b2} \,\mathit {b3}^{2}-4 \mathit {b0} \,\mathit {b2}^{3} \mathit {b3} -4 \mathit {b1}^{3} \mathit {b3}^{2}+\mathit {b1}^{2} \mathit {b2}^{2} \mathit {b3} +\left (-384 a^{2} \mathit {b1} \,\mathit {b3}^{2}+128 a^{2} \mathit {b2}^{2} \mathit {b3} \right ) \textit {\_Z}^{4}+\left (72 a \,\mathit {b1}^{2} \mathit {b3}^{2}-48 a \mathit {b1} \,\mathit {b2}^{2} \mathit {b3} +8 a \,\mathit {b2}^{4}\right ) \textit {\_Z}^{2}\right )^{4}-6 a \mathit {b1} \mathit {b3} \RootOf \left (512 \textit {\_Z}^{6} a^{3} \mathit {b3}^{2}-27 \mathit {b0}^{2} \mathit {b3}^{3}+18 \mathit {b0} \mathit {b1} \mathit {b2} \,\mathit {b3}^{2}-4 \mathit {b0} \,\mathit {b2}^{3} \mathit {b3} -4 \mathit {b1}^{3} \mathit {b3}^{2}+\mathit {b1}^{2} \mathit {b2}^{2} \mathit {b3} +\left (-384 a^{2} \mathit {b1} \,\mathit {b3}^{2}+128 a^{2} \mathit {b2}^{2} \mathit {b3} \right ) \textit {\_Z}^{4}+\left (72 a \,\mathit {b1}^{2} \mathit {b3}^{2}-48 a \mathit {b1} \,\mathit {b2}^{2} \mathit {b3} +8 a \,\mathit {b2}^{4}\right ) \textit {\_Z}^{2}\right )^{2}+2 a \,\mathit {b2}^{2} \RootOf \left (512 \textit {\_Z}^{6} a^{3} \mathit {b3}^{2}-27 \mathit {b0}^{2} \mathit {b3}^{3}+18 \mathit {b0} \mathit {b1} \mathit {b2} \,\mathit {b3}^{2}-4 \mathit {b0} \,\mathit {b2}^{3} \mathit {b3} -4 \mathit {b1}^{3} \mathit {b3}^{2}+\mathit {b1}^{2} \mathit {b2}^{2} \mathit {b3} +\left (-384 a^{2} \mathit {b1} \,\mathit {b3}^{2}+128 a^{2} \mathit {b2}^{2} \mathit {b3} \right ) \textit {\_Z}^{4}+\left (72 a \,\mathit {b1}^{2} \mathit {b3}^{2}-48 a \mathit {b1} \,\mathit {b2}^{2} \mathit {b3} +8 a \,\mathit {b2}^{4}\right ) \textit {\_Z}^{2}\right )^{2}+\textit {\_Z}^{2} \mathit {b3} \right )+x \RootOf \left (512 \textit {\_Z}^{6} a^{3} \mathit {b3}^{2}-27 \mathit {b0}^{2} \mathit {b3}^{3}+18 \mathit {b0} \mathit {b1} \mathit {b2} \,\mathit {b3}^{2}-4 \mathit {b0} \,\mathit {b2}^{3} \mathit {b3} -4 \mathit {b1}^{3} \mathit {b3}^{2}+\mathit {b1}^{2} \mathit {b2}^{2} \mathit {b3} +\left (-384 a^{2} \mathit {b1} \,\mathit {b3}^{2}+128 a^{2} \mathit {b2}^{2} \mathit {b3} \right ) \textit {\_Z}^{4}+\left (72 a \,\mathit {b1}^{2} \mathit {b3}^{2}-48 a \mathit {b1} \,\mathit {b2}^{2} \mathit {b3} +8 a \,\mathit {b2}^{4}\right ) \textit {\_Z}^{2}\right )+c_{1}\right )-432 \left (\mathit {b0} \,\mathit {b3}^{2}-\frac {1}{3} \mathit {b1} \mathit {b2} \mathit {b3} +\frac {2}{27} \mathit {b2}^{3}\right ) \left (a \mathit {b2} \RootOf \left (512 \textit {\_Z}^{6} a^{3} \mathit {b3}^{2}-27 \mathit {b0}^{2} \mathit {b3}^{3}+18 \mathit {b0} \mathit {b1} \mathit {b2} \,\mathit {b3}^{2}-4 \mathit {b0} \,\mathit {b2}^{3} \mathit {b3} -4 \mathit {b1}^{3} \mathit {b3}^{2}+\mathit {b1}^{2} \mathit {b2}^{2} \mathit {b3} +\left (-384 a^{2} \mathit {b1} \,\mathit {b3}^{2}+128 a^{2} \mathit {b2}^{2} \mathit {b3} \right ) \textit {\_Z}^{4}+\left (72 a \,\mathit {b1}^{2} \mathit {b3}^{2}-48 a \mathit {b1} \,\mathit {b2}^{2} \mathit {b3} +8 a \,\mathit {b2}^{4}\right ) \textit {\_Z}^{2}\right )^{2}-\frac {9 \mathit {b0} \mathit {b3}}{16}+\frac {\mathit {b1} \mathit {b2}}{16}\right )}{2 \left (27 \mathit {b0} \,\mathit {b3}^{2}-9 \mathit {b1} \mathit {b2} \mathit {b3} +2 \mathit {b2}^{3}\right ) \left (24 a \mathit {b3} \RootOf \left (512 \textit {\_Z}^{6} a^{3} \mathit {b3}^{2}-27 \mathit {b0}^{2} \mathit {b3}^{3}+18 \mathit {b0} \mathit {b1} \mathit {b2} \,\mathit {b3}^{2}-4 \mathit {b0} \,\mathit {b2}^{3} \mathit {b3} -4 \mathit {b1}^{3} \mathit {b3}^{2}+\mathit {b1}^{2} \mathit {b2}^{2} \mathit {b3} +\left (-384 a^{2} \mathit {b1} \,\mathit {b3}^{2}+128 a^{2} \mathit {b2}^{2} \mathit {b3} \right ) \textit {\_Z}^{4}+\left (72 a \,\mathit {b1}^{2} \mathit {b3}^{2}-48 a \mathit {b1} \,\mathit {b2}^{2} \mathit {b3} +8 a \,\mathit {b2}^{4}\right ) \textit {\_Z}^{2}\right )^{2}-3 \mathit {b1} \mathit {b3} +\mathit {b2}^{2}\right )}$

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