DOC/BUG: also fix mention of covariance matrix later in the tutorial

docs/notebooks/tutorial/nevo.ipynb

@@ -565,7 +565,7 @@
     "2. An unrestricted covariance matrix for random tastes using the product rule.\n",
     "3. A restricted diagonal matrix for random tastes using Monte Carlo Integration.\n",
     "\n",
-    "Notice that the only thing that changes when we estimate the restricted covariance is our initial guess of $\\Sigma_0$. The upper diagonal in this initial guess is ignored because we are optimizing over the lower-triangular Cholesky root of $\\Sigma$."
+    "Notice that the only thing that changes when we estimate the restricted covariance is our initial guess of $\\Sigma_0$. The upper diagonal in this initial guess is ignored because we are optimizing over the lower-triangular Cholesky root of $V = \\Sigma\\Sigma'$."
    ]
   },
   {