Area between a parabola and line?

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SUMMARY

The discussion focuses on calculating the area enclosed by the curves defined by the equations 2y = sqrt(4x), y = 5, and 2y + 3x = 7. The intersection points identified are y = 2 and y = -14/3. The correct approach involves determining the area using the integral A = ∫[a to b] (f(y) - g(y)) dy, with the correct limits and functions. The user initially calculated the area incorrectly as 1000/81 and 841/324, highlighting the importance of accurately identifying the functions and their intersections for proper integration.

PREREQUISITES
  • Understanding of integral calculus, specifically the area between curves.
  • Familiarity with solving equations involving square roots and linear functions.
  • Ability to identify intersection points of functions graphically and algebraically.
  • Knowledge of setting up integrals based on vertical and horizontal strips.
NEXT STEPS
  • Review the method for finding intersection points of curves, particularly for y = sqrt(x) and linear equations.
  • Learn how to set up and evaluate definite integrals for areas between curves.
  • Practice breaking regions into vertical and horizontal strips to determine the appropriate integrals.
  • Explore graphing tools to visualize functions and their intersections for better understanding.
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Students studying calculus, particularly those focusing on integral applications in finding areas between curves, as well as educators looking for examples of complex integration problems.

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Homework Statement



Find the area of the region enclosed by the curves:
2y=sqrt(4x)
y=5 and
2y+3x=7

Homework Equations


A = integral from a to b of f(x)-g(x) dx


The Attempt at a Solution



Tried to integrate this with respect to y.
Found the intersection points to be y=2, -14/3
Then did the integral from -14/3 to 2 of (7/3 - 2y/3) - (1/4y^2)
My answer was 1000/81 but this is incorrect.
Also tried integral from -14/3 to 5 of (7/3 - 2y/3) - (1/4y^2)./
My answer was 841/324 but this was also incorrect.

Thanks to anyone who can help explain this to me, I'm so lost :s
 
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I would recommend you graph all those functions to give you an idea of where all the intersections are. For example y=(7-3x)/2 intersects y=5 in one place. Similarly y=(sqrt4x)/2 intersects y=5 in one place. And y=(7-3x)/2 and y=(sqrt4x)/2 intersect each other in one place. Your job is to sort out which integral to subtract from which to get at the area between all three functions. Hope this helps.
 
In addition to what armolinasf said, the equation 2y = sqrt(4x) can be simplified to y = sqrt(x).

If you break up the region into vertical strips, you will need to use two integrals. If you break the region up into horizontal strips, you'll need only one integral.
 

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