Difference between revisions of "2021 AMC 10A Problems/Problem 19"

(Solution)
(Solution)
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<math>\textbf{(A)} ~18\qquad\textbf{(B)} ~27\qquad\textbf{(C)} ~36\qquad\textbf{(D)} ~45\qquad\textbf{(E)} ~54</math>
 
<math>\textbf{(A)} ~18\qquad\textbf{(B)} ~27\qquad\textbf{(C)} ~36\qquad\textbf{(D)} ~45\qquad\textbf{(E)} ~54</math>
  
==Solution==
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== Solution 1 ==
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<asy>
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size(10cm);
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filldraw(arc((-3,0),3,180,180) -- cycle, gray);
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filldraw(arc((0,3),3,0,180) -- cycle, gray);
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filldraw(arc((3,0),3,180,180) -- cycle, gray);
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filldraw(arc((0,-3),3,180,180) -- cycle, gray);
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filldraw((-3,3)--(3,3)--(3,-3)--(-3,-3)--cycle, grey);
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</asy>
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 +
 
 
https://artofproblemsolving.com/wiki/index.php/File:Image_2021-02-11_111327.png (someone please help link file thanks)
 
https://artofproblemsolving.com/wiki/index.php/File:Image_2021-02-11_111327.png (someone please help link file thanks)
  

Revision as of 17:03, 11 February 2021

Problem 19

The area of the region bounded by the graph of\[x^2+y^2 = 3|x-y| + 3|x+y|\]is $m+n\pi$, where $m$ and $n$ are integers. What is $m + n$?

$\textbf{(A)} ~18\qquad\textbf{(B)} ~27\qquad\textbf{(C)} ~36\qquad\textbf{(D)} ~45\qquad\textbf{(E)} ~54$

Solution 1

[asy] size(10cm);  filldraw(arc((-3,0),3,180,180) -- cycle, gray); filldraw(arc((0,3),3,0,180) -- cycle, gray); filldraw(arc((3,0),3,180,180) -- cycle, gray); filldraw(arc((0,-3),3,180,180) -- cycle, gray); filldraw((-3,3)--(3,3)--(3,-3)--(-3,-3)--cycle, grey); [/asy]


https://artofproblemsolving.com/wiki/index.php/File:Image_2021-02-11_111327.png (someone please help link file thanks)

Video Solution (Using absolute value properties to graph)

https://youtu.be/EHHpB6GIGPc

~ pi_is_3.14