## Quiz: Solve ODEs with Python

**1.** The ODEINT function requires a user defined function that includes time (*t*) and the current system states (*y*). What is the correct definition of the function named *myFunction*?

**A.**def myFunction(t,y):

- Incorrect.

**B.**y,t = myFunction()

- Incorrect.

**C.**def myFunction(y,t):

- Correct.

**D.**def myFunction([t,y]):

- Incorrect.

**2.** The current time (*t*) and system states (*y*) are required as arguments to a custom function for ODEINT in Python. What is returned from the custom function? See ODEINT tutorials for additional help.

**A.**The solution at the next time point: y[k+1]

- Incorrect. The function returns the derivatives at the current time and state values, not the solution.

**B.**A list or array of the differential equation derivatives: dy/dt

- Correct. The user-defined function returns the derivatives at the requested time and state values.

**C.**The time and the solution state values: t, y

- Incorrect. Those are the inputs to the function.

**3.** ODEINT can simultaneously solve coupled differential equations?

**A.**True

- Correct. ODEINT can solve many coupled differential equations, but solution time increases more with >1000 equations.

**B.**False

- Incorrect. Numerical solutions are often possible with many coupled differential equations.