Question

What is meant by the area under a curve?

Answer 1

See the explanation.

Explanation:

We say "the area under a curve", but we mean:

On the rectangular coordinate system, we mean the area under a curve and above the `x`-axis between two value of `x`. (And sometimes, "from one value of `x` to another").

Here is a picture of the are under `y=x^2` from `1` to `3`.

There are variations and complications when speaking to someone in Calculus.

(For example, people sometimes use "the area under the curve" to indicate the NEGATIVE of the area here: