12/10 = 1.2
4/10 = 0.4
1.2-0.4 = 0.8
For

and

, it's helpful to remember the half-angle identities:


So


For

, the Pythagorean identity suffices:

which means

since

.
Answer:
The result of the integral is 
Step-by-step explanation:
We are given the following integral:

I am going to solve by substitution, using
, so
. So, we have

Which has the following result:

Going back to x, the result of the integral is

The answer would be number 1. 173 units^2