MathDB
Intersection Between Two Functions

Source:

March 8, 2009
functionquadraticsspecial factorizations

Problem Statement

Consider the graphs y \equal{} Ax^2 and and y^2 \plus{} 3 \equal{} x^2 \plus{} 4y, where A A is a positive constant and x x and y y are real variables. In how many points do the two graphs intersect? <spanclass=latexbold>(A)</span> exactly 4<spanclass=latexbold>(B)</span> exactly 2 <span class='latex-bold'>(A)</span>\ \text{exactly } 4 \qquad <span class='latex-bold'>(B)</span>\ \text{exactly } 2 <spanclass=latexbold>(C)</span> at least 1, but the number varies for different positive values of A <span class='latex-bold'>(C)</span>\ \text{at least } 1, \text{ but the number varies for different positive values of } A <spanclass=latexbold>(D)</span> 0 for at least one positive value of A<spanclass=latexbold>(E)</span> none of these <span class='latex-bold'>(D)</span>\ 0 \text{ for at least one positive value of } A \qquad <span class='latex-bold'>(E)</span>\ \text{none of these}