# Thread: Evaluate integral using a graph.

1. ## Evaluate integral using a graph.

I know you guys aren't fans of photos, but I was unsure of how to generate this graph online, especially without a function.

The question calls for using the graph to evaluate each integral:

a) $\int^2_0 g(x)dx$

b) $\int^6_2 g(x)dx$

c) $\int^7_0 g(x)dx$

For a) I did the following:

$A= \frac{1}{2} (b \ast h)= \frac{1}{2} (2 \ast 4)= 4$

For b)

$A= -\frac{1}{2} \pi r^2 = -\frac{1}{2}\pi (2)^2= -2\pi$

For c)
I need some help. Would I evaluate it at $\int^7_6$, and then add it to the integrals of a and b?

2. $\displaystyle \int_0^7 g(x) \, dx = \int_0^2 g(x) \, dx + \int_2^6 g(x) \, dx + \int_6^7 g(x) \, dx = 4 - 2\pi + \frac{1}{2}$

3. Great, thanks!