Updated 07_01

Added some more words about interpolation, and little more explanation to provide some context.

nb/07_01_Cuts_Acceptance_Leakage.ipynb

@@ -317,7 +317,17 @@
    "id": "55114f8d",
    "metadata": {},
    "source": [
-    "You could also *interpolate* the `signalAcceptance` and `backgroundLeakage` data arrays to evaluate them numerically given a specific cut value"
+    "You could also *interpolate* the `signalAcceptance` and `backgroundLeakage` data arrays that we just created in order to evaluate these quantities numerically given any specific cut value, rather than just doing our best to read it off a plot for some choice of cut value.\n",
+    "\n",
+    "There are many different ways to interpolate data, the most trivial method being accomplished by just \"connecting the dots\", i.e. building up a piecewise function comprised of linear segments between each data point. If we have data points $(x_i, \\, y_i)$, then the linear interpolating function that describes their relation over the domain $\\{x_i\\}$ is given by,\n",
+    "$$\n",
+    "f_{\\rm interp}(x) = \n",
+    "    \\begin{dcases}\n",
+    "        \\dots, & \\dots \\\\\n",
+    "        \\left(\\frac{y_{i+1} - y_i}{x_{i+1} - x_i}\\right) (x - x_i) + y_i, & x_{i+1} > x \\geq x_i \\\\\n",
+    "        \\dots, & \\dots \\\\\n",
+    "    \\end{dcases}\n",
+    "$$"
    ]
   },
   {