Difference between revisions of "1957 AHSME Problems/Problem 43"

m (typo fix)
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== Solution ==
 
== Solution ==
 +
 +
<asy>
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path p = (0,0){right}..(1,1)..(2,4)..(3,9)..(4,16);
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// Shaded Region
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fill(p--(4,0)--cycle,lightred);
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// x-Axis
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draw((-4,0)--(16,0), arrow=Arrows);
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label("$x$",(18,0));
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// y-Axis
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draw((0,-4)--(0,16), arrow=Arrows);
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label("$y$",(0,18));
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// y=x^2
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draw(p);
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// x=4
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draw((4,-5)--(4,20), arrow=Arrows(TeXHead));
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</asy>
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<math>\boxed{\textbf{(B) }35}</math>.
 
<math>\boxed{\textbf{(B) }35}</math>.
  

Revision as of 09:38, 27 July 2024

Problem

We define a lattice point as a point whose coordinates are integers, zero admitted. Then the number of lattice points on the boundary and inside the region bounded by the $x$-axis, the line $x = 4$, and the parabola $y = x^2$ is:

$\textbf{(A)}\ 24 \qquad  \textbf{(B)}\ 35\qquad  \textbf{(C)}\ 34\qquad  \textbf{(D)}\ 30\qquad  \textbf{(E)}\ \infty$

Solution

[asy]  path p = (0,0){right}..(1,1)..(2,4)..(3,9)..(4,16);  // Shaded Region fill(p--(4,0)--cycle,lightred);  // x-Axis draw((-4,0)--(16,0), arrow=Arrows); label("$x$",(18,0));  // y-Axis draw((0,-4)--(0,16), arrow=Arrows); label("$y$",(0,18));  // y=x^2 draw(p);  // x=4 draw((4,-5)--(4,20), arrow=Arrows(TeXHead));  [/asy]

$\boxed{\textbf{(B) }35}$.

See Also

1957 AHSC (ProblemsAnswer KeyResources)
Preceded by
Problem 42
Followed by
Problem 44
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All AHSME Problems and Solutions

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