The Runge-Kutta method is used to approximate solutions of ordinary differential equations (ODEs). The 3rd order Runge-Kutta method (RK3) can be expressed by the formula:
\[ y = y_0 + \frac{1}{6}(k_1 + 2k_2 + 3k_3) \]
Where:
Thus, the correct formula for the Runge-Kutta 3rd order method is:
\[ y = y_0 + \frac{1}{6}(k_1 + 2k_2 + 3k_3) \]
This corresponds to option (A).
Let \( y = f(x) \) be the solution of the differential equation\[\frac{dy}{dx} + \frac{xy}{x^2 - 1} = \frac{x^6 + 4x}{\sqrt{1 - x^2}}, \quad -1 < x < 1\] such that \( f(0) = 0 \). If \[6 \int_{-1/2}^{1/2} f(x)dx = 2\pi - \alpha\] then \( \alpha^2 \) is equal to ______.
Let \( y = y(x) \) be the solution of the differential equation \[ \frac{dy}{dx} + 2y \sec^2 x = 2 \sec^2 x + 3 \tan x \cdot \sec^2 x \] such that \( y(0) = \frac{5}{4} \). Then \[ 12 \left( y\left( \frac{\pi}{4} \right) - e^{-2} \right) \] is equal to _____.