document.write( "Question 1027807: Please help me with these problem did any of this before.
\n" ); document.write( " Give an example of each of the following: \r
\n" ); document.write( "\n" ); document.write( " a. A function with vertical asymptotes at x=-3 and x=1, and a horizontal asymptote at y=2. \r
\n" ); document.write( "\n" ); document.write( " b. A word problem whose solution is 12!/9!3! \r
\n" ); document.write( "\n" ); document.write( " c. The equation of an ellipse with vertices at (0,0) and (-8,0). \r
\n" ); document.write( "\n" ); document.write( " d. A logarithmic expression equivalent to 5.
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Algebra.Com's Answer #643091 by KMST(5328)\"\" \"About 
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a. To have those vertical asymptotes, a rational functions should have in the denominator the factors
\n" ); document.write( "\"%28x-%28-3%29%29=%28x%2B3%29\" and \"%28x-1%29\" .
\n" ); document.write( "With \"%28x%2B3%29%28x-1%29=x%5E2%2B2x-3\" for a denominator
\n" ); document.write( "a rational function with \"y=2\" for a horizontal asymptote
\n" ); document.write( "must have for a numerator a quadratic polynomial with \"2\" for a leading coefficient.
\n" ); document.write( "\"2x%5E2\" is a suitable numerator for that, and its value for \"x=-3\" and for \"x=1\" is not zero.
\n" ); document.write( "So, \"highlight%28f%28x%29=2x%5E2%2F%28x%5E2%2B2x-3%29%29\" has all the required asymptotes.\r
\n" ); document.write( "\n" ); document.write( "FURTHER EXPLANATION:
\n" ); document.write( "A rational function may have vertical asymptotes at the values of \"x\" that make
\n" ); document.write( "the denominator zero.
\n" ); document.write( "So, \"f%28x%29=%28x%2B2%29%2F%28x-1%29\" does not exist for \"x=1\" ,
\n" ); document.write( "and has \"x=1\" as a vertical asymptote,
\n" ); document.write( "because at valued close to \"x=1\" the numerator is close to \"1%2B2=3\" ,
\n" ); document.write( "but as \"x\" approaches \"1\", the denominator approaches zero,
\n" ); document.write( "making \"abs%28f%28x%29%29\" increase without bounds.
\n" ); document.write( "However, if a value of \"x\" makes both, numerator and denominator zero,
\n" ); document.write( "there may not be a vertical asymptote at that value.
\n" ); document.write( "For example, \"f%28x%29=%28x-1%29%28x%2B2%29%2F%28x-1%29\" does not exist for \"x=1\" , but \"f%28x%29=x%2B2\" for all \"x%3C%3E1\" , so within its domain \"f%28x%29\" is just a linear function,
\n" ); document.write( "and graphs as a slanted line, with a hole at the point (1,3), and no vertical asymptote.
\n" ); document.write( "On the other hand, \"g%28x%29=%28x-1%29%28x%2B2%29%2F%28x-1%29%5E2\" is {{g(x)=(x+2)/(x-1)}}} for \"x%3C%3E1\" ,
\n" ); document.write( "and has \"x=1\" for a vertical asymptote.
\n" ); document.write( "A rational function has a horizontal asymptote \"y=k\" for some number \"k\"
\n" ); document.write( "when numerator and denominator are polynomials of the same degree, and the ratio of the leading coefficients is \"k\".
\n" ); document.write( "It is obvious that \"f%28x%29=%282x%5E2%2B1%29%2Fx%5E2=2%2B1%2Fx%5E2\" has \"y=2\" for a vertical asymptote,
\n" ); document.write( "but so does .
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\n" ); document.write( "b. How many different possibilities has an academic coach trying to choose a team of 3 students to represent the school in an academic contest? (The order the team members are chosen or listed does not matter).
\n" ); document.write( "EXPLANATION:
\n" ); document.write( "Choosing a set of \"3\" from a larger set of \"12\" , is a question of combinations, because the choosing order, position, or role of each team member is not important.
\n" ); document.write( "When choosing, there are \"12\" possibilities for the first choice, \"12-1=11\" for the second choice, and \"1-2=10\" for the third choice.
\n" ); document.write( "That is .
\n" ); document.write( "But there are \"3%21=3%2A2%2A1\" ways to choose the same team, because any of the {{[3}}} members could have been chosen first, followed in each case, by any of the {{[3-1=2}}} other members, leaving just \"2-1=1\" choice.
\n" ); document.write( "So there may be \"12%21%2F9%21\" lists of \"3\" members, but since each set of \"3\" can be listed \"3%21\" ways, there are really \"12%21%2F%289%21%2A3%21%29\" teams.
\n" ); document.write( "NOTE: An alternate word problem is
\n" ); document.write( "How many different cheerleading team of \"9\" members can be chosen from \"12\" students showing up at the tryouts?
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\n" ); document.write( "c. The equation of an ellipse with vertices at (0,0) and (-8,0) could be
\n" ); document.write( "\"%28x%2B4%29%5E2%2F16%2By%5E2=1\" .
\n" ); document.write( "EXPLANATION:
\n" ); document.write( "The points called vertices are the ends of the major axis, since the ends of the minor axis are usually called co-vertices.
\n" ); document.write( "The given points are on a horizontal line (axis), so the segments between them has to be the horizontal major axis.
\n" ); document.write( "Since the distance between the vertices is \"0-%28-8%29=8\" , the semi-major axis is \"8%2F2=4\" , and the equation of the ellipse must be \"%28x%2B4%29%5E2%2F16%2By%5E2%2Fb%5E2=1\" with any \"b\" (the semi-minor axis) such that \"0%3Cb%3C4\" .
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\n" ); document.write( "d. \"log%28100000%29\" is a logarithmic expression equivalent to 5. So is \"log%282%2C32%29\" .
\n" ); document.write( "EXPLANATION:
\n" ); document.write( "\"100000=10%5E5\" so \"log%28100000%29=log%2810%2C100000%29=log%2810%2C10%5E5%29=5\" , and
\n" ); document.write( "\"2%5E5=32\" so \"log%282%2C32%29=log%282%2C2%5E5%29=5\" .
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