
...a differential to solve for the area
under a CURVE?
The Big Bang Theory Season 1, Episode 1

We're getting to know each other.
There's a learning CURVE.
The Big Bang Theory Season 3, Episode 2

Now assuming the left side of a bell CURVE
peaking around the present...
The Big Bang Theory Season 4, Episode 1

This is a complex battle simulation
with a steep learning CURVE.
The Big Bang Theory Season 1, Episode 7

there was a learning CURVE,
The Big Bang Theory Season 10, Episode 5