Calc 2 Integration Area Problem

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Alexa
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Homework Statement


Please help me solve the calc problem pictured!

Homework Equations


y=3-x^2 and y=x+1

The Attempt at a Solution


My attempt is in one of the photos!
 
Attachments
  • Online homework screen with the region R bounded by y = 3 − x² and y = x + 1, and an area integral A = ∫ from 1 to 2 of (sqrt(3−y) − (y−1)) dy + ∫ from 2 to 3 of (sqrt(3−y) − 2) dy, with a red cross on the second integrand and green ticks on the limits and the answer 2.
    Screen Shot 2018-05-16 at 4.43.41 PM.png
    27.8 KB · Views: 532
  • Desmos graph of the parabola y = 3 - x^2 in red and the line y = x + 1 in blue, intersecting at (1, 2) and (-2, -1), with the axes labelled from -2 to 2 and 1 to 4.
    Screen Shot 2018-05-16 at 4.43.35 PM.png
    15.4 KB · Views: 603
Alexa said:

Homework Statement


Please help me solve the calc problem pictured!

Homework Equations


y=3-x^2 and y=x+1

The Attempt at a Solution


My attempt is in one of the photos!
Type the problem statement, and your solution. Your images are not readable on my devices, and so I am unable to help or give hints.

For more on this issue, see the post "Guidelines for students and helpers", by Vela.
 
The region R is bounded by y=3−x^2 and y=x+1.
The area of the region can be found by integrating: integral from 1 to 2 ______dy + integral from 2 to 3 ______dy
For the first blank I had (sqrt(3-y))-(y-1) and for the second I had (sqrt(3-y)-2)
These are both wrong according to the system
 
Alexa said:
The region R is bounded by y=3−x^2 and y=x+1.
The area of the region can be found by integrating: integral from 1 to 2 ______dy + integral from 2 to 3 ______dy
For the first blank I had (sqrt(3-y))-(y-1) and for the second I had (sqrt(3-y)-2)
These are both wrong according to the system

So, the problem statement is asking you to find the area the hard way; integrating with respect to ##x## would be a lot easier.

Anyway, to see the ##x##-limits in the ##y##-integrals, you should start by drawing a picture of your region. The first (vertically lower) region goes from a negative value of ##y## to a positive value, and for each such ##y##, from a smaller (sometimes negative, sometimes positive) value of ##x## to a larger value of ##x##---giving a positive ##x##-length. You have your first integral going from a large value of ##x## to a smaller one---giving a negative ##x##-length.

You seem to be assuming that ##x## must be positive, but that is not stated anywhere in the problem as you wrote it.
 
Alexa said:
The region R is bounded by y=3−x^2 and y=x+1.
The area of the region can be found by integrating: integral from 1 to 2 ______dy + integral from 2 to 3 ______dy
For the first blank I had (sqrt(3-y))-(y-1) and for the second I had (sqrt(3-y)-2)
These are both wrong according to the system
Could you explain to us how you came up with your attempt?