Direct integration equations
#003
Simulation & Code
Computational workSimulation

Python codeOpen
import numpy as np
import matplotlib.pyplot as plt
x = np.linspace(-2, 2, 800)
with np.errstate(divide="ignore", invalid="ignore", over="ignore"):
y = x**5 - x**2 + 7*x
y_prime = 5*x**4 - 2*x + 7
plt.figure(figsize=(8, 5))
plt.plot(x, y, label="y = x^5 - x^2 + 7x", linewidth=2)
plt.plot(x, y_prime, label="y' = 5x^4 - 2x + 7", linewidth=2, color="red")
plt.title("Entry #003: solution and derivative")
plt.xlabel("x")
plt.ylabel("value")
plt.grid(True, alpha=0.35)
plt.legend()
plt.tight_layout()
plt.show()
Handwritten derivation
Download full PDFTakeaway & Interpretation
This equation says the solution's slope is controlled entirely by 5x^4 - 2x + 7. After integrating, the solution family becomes y = x^5 - x^2 + 7x + C, meaning every solution has the same overall shape but may be shifted vertically by the constant C.