Typo in Tutorial 3 (#471)

Author: akleeman

tutorials/tutorial_3_one_dimension_sparse.ipynb

@@ -407,7 +407,7 @@
     "- Compute $D = \\mbox{diag}[K_{ff} - Q_{ff} + \\sigma_{\\epsilon}^2]$ which will require building $Q_{ff} = K_{fu} K_{uu}^{-1} K_{uf}$ (or better yet, just finding the diagonal of the result)\n",
     "- Compute $S = K_{uu} + K_{uf} D^{-1} K_{fu}$\n",
     "- Compute $\\mu = K_{*u} S^{-1} K_{uf} D^{-1} y$\n",
-    "- Compute $V = K_{**} - K_{**} - K_{*u} K_{uu}^{-1} K_{u*} + K_{*u} S^{-1} K_{u*}$\n",
+    "- Compute $V = K_{**} - K_{*u} K_{uu}^{-1} K_{u*} + K_{*u} S^{-1} K_{u*}$\n",
     "There are a lot of different ways to go about this, and plenty of room for optimization ... but probably best to ignore such optimizations for this example.\n",
     "- Return $\\mathbf{f^*}|y \\sim \\mathcal{N}(\\mu, V)$"
    ]