Friday

September 4, 2015
Posted by **Donna** on Thursday, July 11, 2013 at 9:15pm.

I keep getting an area around 21.3 but it is incorrect. Am I close?

Thank you!

- Calculus -
**Steve**, Friday, July 12, 2013 at 11:57amodd that one function is written as

2y = 4√x

why not just y = 2√x ?

Anyway, assuming the functions are correctly written, the area is roughly triangular, with vertices at (-1,4),(1,2),(4,4)

Integrating along x, we need to divide it up into two regions, over [-1,1] and [1,4]

a = ∫[-1,1] 4 - (3-x) dx + ∫[1,4] 4 - 2√x dx

= (x + 1/2 x^2)[-1,1] + (4x - 4/3 x^(3/2))[1,4]

= 2 + 8/3

= 14/3

Integrating along y is easier, since we just subtract the left from the right:

a = ∫[2,4] y^2/4 - (3-y) dy

= y^3/12 + y^2/2 - 3y [2,4]

= 14/3