Does this method make sense written down this way?

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The discussion centers on solving the differential equation \(\frac{d^2y}{dx^2}=3x^2-10x+3\). The initial attempt at a solution incorrectly applied integration, leading to confusion regarding the mathematical validity of the steps taken. The correct approach involves integrating the right-hand side of the equation directly, resulting in \(\frac{dy}{dx}=x^3-5x^2+3x+C_1\) and subsequently integrating again to find \(y\), which includes an additional constant of integration.

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Homework Statement



Solve the differential equation: [tex]\frac{d^2y}{dx^2}=3x^2-10x+3[/tex]

The Attempt at a Solution



[tex]\int\int \frac{d}{dx}\frac({dy}{dx})3x^2-10x+3=\frac{1}{4}x^4-\frac{5}{3}x^3+\frac{3}{2}x^2+c[/tex]

Does that make sense mathematically?
 
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studentxlol said:

Homework Statement



Solve the differential equation: [tex]\frac{d^2y}{dx^2}=3x^2-10x+3[/tex]

The Attempt at a Solution



[tex]\int\int \frac{d}{dx}(\frac{dy}{dx})3x^2-10x+3=\frac{1}{4}x^4-\frac{5}{3}x^3+\frac{3}{2}x^2+c[/tex]

Does that make sense mathematically?
...
No. Not even if you fix the parentheses.

[itex]\displaystyle\int\frac{d}{dx}\left(\frac{dy}{dx} \right)dx=\int\left(3x^2-10x+3\right)dx[/itex]

[itex]\displaystyle\frac{dy}{dx}=x^3-5x^2+3x+C_1[/itex]

So that: [itex]\displaystyle y=\int\left\{\int\frac{d}{dx}\left( \frac{dy}{dx} \right)dx\right\}dx=\int\left(x^3-5x^2+3x+C_1\right)dx[/itex]
which has an additional constant of integration.​
 

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