# Thread: Help with area problem

1. ## Help with area problem

Find the smaller of the two regions created by the curves x+7y=25 and x^2+y^2=25.

2. Originally Posted by nickels
Find the smaller of the two regions created by the curves x+7y+25
You'll need an equals sign for this if the question is to make sense, do you mean x+7y=25?

Originally Posted by nickels
and x^2+y^2=25.
This is a circle centred at the origin, what is it's radius?

3. oh yes, sorry
i meant x+7y=25

4. I would say the area is equal to $\displaystyle \int_a^b\sqrt{25-x^2}- \frac{25-x}{7}~dx$ where $a$ and $b$ are the intersections between the two functions.

Do you follow?

5. Yes, I follow, but when I try to solve the integral, I mess up

6. Originally Posted by nickels
Yes, I follow, but when I try to solve the integral, I mess up
Separate into two parts

$\displaystyle \int_a^b\sqrt{25-x^2}~dx-\int_a^b \frac{25-x}{7}~dx$

For the first part use the substitution $x=5\tan u$ the second one is a gimme!

7. I'm still a little lost

8. Why did you delete your posts?