Riley, did you know I like looking at the stars at night? {{CMD_7}} Stars are freaking awesome balls of nuclear fire whose light took thousands of years to reach us. {{CMD_8}} I know! But did you know that the best way to see a very dim star is to look {{CMD_9}}near{{CMD_10}} it but {{CMD_11}}not exactly at{{CMD_12}} it? It's because then you can use the ``rods'' in your eye, which work better in low light than the ``cones'' in your eyes. {{CMD_13}} That's amazing! Hey, that reminds me of when we were talking about the two functions {{MATH_14}} which we now know are completely different functions. {{CMD_15}} Whoa. How are you seeing a connection here? {{CMD_16}} If we want to understand what is happening with the function {{MATH_17}} at {{MATH_18}}, we can't do it by setting {{MATH_19}}. Instead we need to look {{CMD_20}}near{{CMD_21}} {{MATH_22}} but {{CMD_23}}not exactly at{{CMD_24}} {{MATH_25}}. {{CMD_26}} Ah ha! Because if we are {{CMD_27}}not exactly at{{CMD_28}} {{MATH_29}}, then {{MATH_30}} {{CMD_31}}