Question

How do you find the area bounded by the x axis, y axis and x+y=4?

Answer 1

Calculus

Explanation:

y = -x+4

so we have to find the intersection. They "y axis" means that x = 0, so that is the lower bound of the integral. To find the upper bound, we have to find where y=-x+4 crosses the x axis. That occurs when x = 4.

So we can set up the integral: `int_0^4 (-x+4) dx`
which is `[-0.5x^2 + 4x]_0^4`
which is 8.

That should be the answer I think.