We want to iterate over the x′s and the y′s. The Euler method tells us to choose the sequences defined by:

\[ x_{n+1} = x_n + 0.1, \quad y_{n+1} = y_n + 0.1 \cdot (x_n - y_n^2) \]

The initial conditions are \( x_1 = 1.3 \) and \( y_1 = 2.35 \).

1. Create a new document, press , and select Add Calculator.
2. Press and select Actions > Define.
3. Define \( u(n) \): Enter the initialization on the first line and the recursive expression on the second line.
4. Define \( v(n) \): Similarly, input the initialization and recursive formula for \( v(n) \).

   

To compute \( y(2.2) \), recall that \( u(10) = x_{10} = 2.2 \). Therefore, \( v(10) = y_{10} \approx y(2.2) \).

1. Enter \( u(10) \) to confirm \( x_{10} = 2.2 \).
2. Enter \( v(10) \). The result should be \( v(10) = 1.42 \), giving: \[ y(2.2) \approx 1.42 \]