Calculus I · Limits and Continuity · practice
Infinite Limits and Asymptote Practice
Visual study stop
Read the picture before the symbols
Pause at each graph long enough to say what the input is doing, what the output is doing, and which feature supports the next mathematical decision.
Read this graph as text
Odd and even powers at a vertical asymptote. Two ordered panels share the vertical asymptote x = 1. In the odd-power panel, y = 1/(x - 1) falls without bound from the left and rises without bound from the right. In the even-power panel, y = 1/(x - 1) squared rises without bound from both sides. Each panel uses explicit left and right domains and a dashed asymptote.
The odd-power curves are solid, the even-power curves are double-stroked, and both panels mark x = 1 with a dashed line and title.
Why it matters: Compare one-sided signs for reciprocal functions with odd and even denominator powers.
Compare odd and even denominator powers before calculating. The parity determines whether the sign changes across the excluded input or remains the same on both sides.
Read this graph as text
Approaching a horizontal asymptote. The rational curve f(x) = (3x squared - 2x + 5)/(x squared + 4) is drawn from x = -12 to x = 12. Its denominator never vanishes for real x. A dashed horizontal line marks y = 3, and both ends of the solid curve move closer to that line, showing equal limits at positive and negative infinity.
The function is a heavy solid curve and the asymptote is a dashed line labeled y = 3.
Why it matters: Connect equal-degree rational end behavior to the ratio of leading coefficients.
At infinity, the graph is not approaching a finite input. Follow the long-run trend and use dominant terms to identify the horizontal level the outputs settle toward.
Section 4 Exercises
A. One-sided infinite limits
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Answer 1 from the source-traced unit appendix.Show answer
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Answer 2 from the source-traced unit appendix.Show answer
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Answer 3 from the source-traced unit appendix.Show answer
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Answer 4 from the source-traced unit appendix.Show answer
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Answer 5 from the source-traced unit appendix.Show answer
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Answer 6 from the source-traced unit appendix.Show answer
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Answer 7 from the source-traced unit appendix.Show answer
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Answer 8 from the source-traced unit appendix.Show answer
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Answer 9 from the source-traced unit appendix.Show answer
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Answer 10 from the source-traced unit appendix.B. Holes and vertical asymptotes
Find and classify discontinuities of .
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Hole at ; vertical asymptote at .
Answer 11 from the source-traced unit appendix.Find and classify discontinuities of .
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Hole at ; vertical asymptote at .
Answer 12 from the source-traced unit appendix.Find all holes and vertical asymptotes of .
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Hole at ; vertical asymptote at .
Answer 13 from the source-traced unit appendix.Determine one-sided behavior at every vertical asymptote of .
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At : left , right . At : left , right .
Answer 14 from the source-traced unit appendix.Determine one-sided behavior at every vertical asymptote of .
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Both one-sided limits at are .
Answer 15 from the source-traced unit appendix.Explain why a cancelled denominator factor creates a hole rather than a vertical asymptote.
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Cancellation removes the zero factor for nearby inputs, leaving a finite limiting value.
Answer 16 from the source-traced unit appendix.C. Rational limits at infinity
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Answer 17 from the source-traced unit appendix.Show answer
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Answer 18 from the source-traced unit appendix.Show answer
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Answer 19 from the source-traced unit appendix.Show answer
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Answer 20 from the source-traced unit appendix.Show answer
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Answer 21 from the source-traced unit appendix.Show answer
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Answer 22 from the source-traced unit appendix.Show answer
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Answer 23 from the source-traced unit appendix.Find all horizontal asymptotes of .
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Horizontal asymptote .
Answer 24 from the source-traced unit appendix.Find the slant asymptote of .
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Slant asymptote .
Answer 25 from the source-traced unit appendix.Use division to describe the end behavior of .
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Polynomial asymptote .
Answer 26 from the source-traced unit appendix.D. Radicals at infinity
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Answer 27 from the source-traced unit appendix.Show answer
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Answer 28 from the source-traced unit appendix.Show answer
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Answer 29 from the source-traced unit appendix.Show answer
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Answer 30 from the source-traced unit appendix.Show answer
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Answer 31 from the source-traced unit appendix.Show answer
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Answer 32 from the source-traced unit appendix.Show answer
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Answer 33 from the source-traced unit appendix.Explain the exact point where must be used in a radical-at-infinity problem.
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Use ; at negative infinity .
Answer 34 from the source-traced unit appendix.E. Mixed exam practice
Analyze all discontinuities and asymptotes of .
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Hole at , vertical asymptote , horizontal asymptote ; one-sided limits at : .
Answer 35 from the source-traced unit appendix.Analyze all discontinuities and asymptotes of .
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Hole at , vertical asymptote , horizontal asymptote ; one-sided limits at : .
Answer 36 from the source-traced unit appendix.Find the exact one-sided limits at every vertical asymptote of .
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At : left , right . At : left , right .
Answer 37 from the source-traced unit appendix.Find the end behavior of , including any polynomial asymptote.
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Polynomial asymptote .
Answer 38 from the source-traced unit appendix.Construct a rational function with a hole at , a vertical asymptote at , and horizontal asymptote .
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Example: .
Answer 39 from the source-traced unit appendix.Explain why a graph may cross a horizontal asymptote but cannot take a finite value on a vertical asymptote where its formula is undefined.
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Horizontal asymptotes describe end behavior and may be crossed; a vertical asymptote occurs at an excluded finite input where the function is unbounded.
Answer 40 from the source-traced unit appendix.Answers begin in the referenced section.
After the explanation
Use the section idea
Is the function growing without bound near a finite input, or settling into end behavior as the input grows?
Vertical asymptotes describe local blow-up near an excluded finite input; end-behavior asymptotes describe the long-run trend as inputs grow in magnitude.
Near a denominator zero, build a sign chart for each side; at infinity, compare dominant powers or divide to expose the lasting term.
Do not merge positive and negative infinity, and remember that square roots produce absolute values when factoring a large squared input.
You understand the section when you can predict signs and asymptotes before doing detailed algebra, then verify them with the expression.
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