3.15 problem 10

3.15.1 Solving as quadrature ode
3.15.2 Maple step by step solution

Internal problem ID [12628]
Internal file name [OUTPUT/11281_Friday_November_03_2023_06_29_40_AM_41313843/index.tex]

Book: Ordinary Differential Equations by Charles E. Roberts, Jr. CRC Press. 2010
Section: Chapter 2. The Initial Value Problem. Exercises 2.1, page 40
Problem number: 10.
ODE order: 1.
ODE degree: 1.

The type(s) of ODE detected by this program : "quadrature"

Maple gives the following as the ode type

[_quadrature]

\[ \boxed {y^{\prime }-y^{2}=1} \]

3.15.1 Solving as quadrature ode

Integrating both sides gives \begin {align*} \int \frac {1}{y^{2}+1}d y &= x +c_{1}\\ \arctan \left (y \right )&=x +c_{1} \end {align*}

Solving for \(y\) gives these solutions \begin {align*} y_1&=\tan \left (x +c_{1} \right ) \end {align*}

Summary

The solution(s) found are the following \begin{align*} \tag{1} y &= \tan \left (x +c_{1} \right ) \\ \end{align*}

Figure 122: Slope field plot

Verification of solutions

\[ y = \tan \left (x +c_{1} \right ) \] Verified OK.

3.15.2 Maple step by step solution

\[ \begin {array}{lll} & {} & \textrm {Let's solve}\hspace {3pt} \\ {} & {} & y^{\prime }-y^{2}=1 \\ \bullet & {} & \textrm {Highest derivative means the order of the ODE is}\hspace {3pt} 1 \\ {} & {} & y^{\prime } \\ \bullet & {} & \textrm {Solve for the highest derivative}\hspace {3pt} \\ {} & {} & y^{\prime }=1+y^{2} \\ \bullet & {} & \textrm {Separate variables}\hspace {3pt} \\ {} & {} & \frac {y^{\prime }}{1+y^{2}}=1 \\ \bullet & {} & \textrm {Integrate both sides with respect to}\hspace {3pt} x \\ {} & {} & \int \frac {y^{\prime }}{1+y^{2}}d x =\int 1d x +c_{1} \\ \bullet & {} & \textrm {Evaluate integral}\hspace {3pt} \\ {} & {} & \arctan \left (y\right )=x +c_{1} \\ \bullet & {} & \textrm {Solve for}\hspace {3pt} y \\ {} & {} & y=\tan \left (x +c_{1} \right ) \end {array} \]

Maple trace

`Methods for first order ODEs: 
--- Trying classification methods --- 
trying a quadrature 
trying 1st order linear 
trying Bernoulli 
trying separable 
<- separable successful`
 

Solution by Maple

Time used: 0.0 (sec). Leaf size: 8

dsolve(diff(y(x),x)=1+y(x)^2,y(x), singsol=all)
 

\[ y \left (x \right ) = \tan \left (c_{1} +x \right ) \]

Solution by Mathematica

Time used: 0.145 (sec). Leaf size: 24

DSolve[y'[x]==1+y[x]^2,y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to \tan (x+c_1) \\ y(x)\to -i \\ y(x)\to i \\ \end{align*}