$$\iint e^{x+y}\,dA$$
domain defined by:$$\{x\ge 5\:\:\:,\:y\ge 5\:\:,\:x+y\le 16\}$$
This is what I'm given and I'm asked to solve this.
I know the formula $a\le x\le b\:\:,\:g_1\left(x\right)\le y\le g_2\left(x\right)$.
But I'm not sure how I would find those components.
I got this so far:
$$a=5, b=16$$
And I'm not sure what $g_1(x)$ or the other g is.
How would I find that?
Make a sketch of those limits. For $x\ge 5$, draw a vertical line at that value, and you know that your domain is to the right. For $y\ge 5$, draw a horizontal line at $y=5$, and your domain is above that line. Similarly, $x+y=16$ is a line that connects $(16,0)$ and $(0,16)$, and your domain is below that.
With this information, your domain is a triangle. Calculate the intersection points. You should get the vertices at $(5,5)$, $(5,11)$ and $(11,5)$. Then $x$ varies between $5$ and $11$, and $y$ varies between $5$ and $16-x$. Or, if you change the order of integration, $y$ varies between $5$ and $11$, and $x$ between $5$ and $16-x$.