Direct integration equations
#009
Problem
Classification
- exponential antiderivative
- solution family
Method
- direct integration
Solution
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 = np.exp(2*x)
y_prime = 2*np.exp(2*x)
plt.figure(figsize=(8, 5))
plt.plot(x, y, label="y = e^(2x)", linewidth=2)
plt.plot(x, y_prime, label="y' = 2e^(2x)", linewidth=2, color="red")
plt.title("Entry #009: 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 2e^(2x). After integrating, the solution family becomes y = e^(2x) + C, meaning every solution has the same overall shape but may be shifted vertically by the constant C. This function grows at a rate proportional to itself; more specifically, its derivative is one-half of the original exponential form.