# Thread: Finding the finite area between curves

1. ## Finding the finite area between curves

y=1-x^2 ,y=9x-21

I understand the integral formula is

$$\int_{a}^{b} [f(x)-g(x)] dx$$

to find the a and b values what should I do ?

I understand the 1 - x^2 is a parabola that goes downwards and the 9x-21 is a line

Thanks

2. ## Re: Finding the finite area between curves

Originally Posted by bee77
y=1-x^2 ,y=9x-21
I understand the integral formula is
$$\int_{a}^{b} [f(x)-g(x)] dx$$to find the a and b values what should I do ?
I understand the 1 - x^2 is a parabola that goes downwards and the 9x-21 is a line
Set $1-x^2=9x-21$ and solve. See HERE

3. ## Re: Finding the finite area between curves

Thanks Plato I had a look at some youtube videos and I just got lost ...the solutions state x = 2 and x = -11 so those values would be the b = 2 and a = -11 respectively then I just simply integrate ...cheers

4. ## Re: Finding the finite area between curves

The final answer is A =2197/6 units^2
in the work sheet ...I seem to get different

5. ## Re: Finding the finite area between curves

Originally Posted by bee77
The final answer is A =2197/6 units^2
in the work sheet ...I seem to get different
SEE HERE

6. ## Re: Finding the finite area between curves

Thnaks Plato ,I can see I made a simple algebra mistake with the 21 becoming 22 in the integration part ...cheers