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

m (typo fix)
(diagram)
Line 11: Line 11:
  
 
== Solution ==
 
== 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>
 +
 
<math>\boxed{\textbf{(B) }35}</math>.
 
<math>\boxed{\textbf{(B) }35}</math>.
  

Revision as of 10:38, 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
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
All AHSME Problems and Solutions

The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions. AMC logo.png