Updating make_subplots on Plotly

I was wondering if there was a way to update subplots. I realise I could just start of with adding two 2 subplots to the original figure however that's not what I'm looking for in an ideal situation. Thanks

x_values = np.arange(10)
y_values_one = x_values*3 + 5 
y_values_two = x_values**2 - 5

fig = make_subplots(rows=1,cols=1)
fig.add_trace(go.Scatter(
    x=x_values,
    y=y_values_one,
    mode='lines'),
row=1,col=1)

#Method to add another row to subplots?

fig.add_trace(go.Scatter(
    x=x_values,
    y=y_values_two,
    mode='lines'),
row=2,col=1)
fig.show()