### Strange Error Message when Plotting with a LaTeX Legend

The following code is from the 1st edition of my textbook, *Sage for Undergraduates*. It is producing some extremely unexpected errors (technically, deprication warnings). Something about an invalid escape sequence, `\i`

, which I'm not using.

Can someone explain how I should change my code, so that these warnings do not appear?

~~Code:
~~Code:

`P1= text('$\int_0^2 \sqrt{x} \, dx$', (0.5, 1.1), `~~fontsize=20)
~~fontsize=20)

`P2= plot( sqrt(x), 0, 2, `~~fill=True)
~~fill=True)

`P= P1 + `~~P2
~~P2

`P.show()`

Warning:

`<input>:1: DeprecationWarning: invalid escape sequence \i`

Quick Link:
~~https://sagecell.sagemath.org/?z=eJwVy8EKAiEURuF90Dv8i4FREtELLe87uGgptclIkLHGG0nRu-fszuI7wTMkdVHzFPMiF3cmxPZc5dt_iAbXPs0GytmjgbdeG9zqIi1_EpPT-10gxqNUUdgm1QdwBjRYLoVP6yttiBE8Dgg02rZ7fSv9B0vRIXA=&lang=sage&interacts=eJyLjgUAARUAuQ== ~~https://sagecell.sagemath.org/?z=eJwVy8EKAiEURuF90Dv8i4FREtELLe87uGgptclIkLHGG0nRu-fszuI7wTMkdVHzFPMiF3cmxPZc5dt_iAbXPs0GytmjgbdeG9zqIi1_EpPT-10gxqNUUdgm1QdwBjRYLoVP6yttiBE8Dgg02rZ7fSv9B0vRIXA=&lang=sage&interacts=eJyLjgUAARUAuQ==