Analytical Approximate Solutions for the Cubic-Quintic Duffing Oscillator in Terms of Elementary Functions

Figure 7

Difference between normalized numerical and approximate solutions for: (orange) 𝜆₁=1, 𝜆₃=10, 𝜆₅=1, and 𝐴=1, (blue) 𝜆₁=5, 𝜆₃=3, 𝜆₅=1, and 𝐴=3; (green) 𝜆₁=1, 𝜆₃=1, 𝜆₅=1, and 𝐴=3; (red) 𝜆₅𝐴⁴→∞.