End behaviour of a polynomial

Use the leading term to predict what happens at both ends of the graph.

  • Find the degree and the sign of the leading coefficient.
  • An even degree gives the same direction at both ends; an odd degree gives opposite directions.
  • A positive leading coefficient makes the right end rise; a negative one makes it fall.
DegreeLeading coefficientLeft endRight end
EvenPositiveRisesRises
EvenNegativeFallsFalls
OddPositiveFallsRises
OddNegativeRisesFalls

Example 1

Odd degree, negative coefficient

Describe both ends of the graph using words or arrow notation.

Left end rises; right end falls...

Example 2

Even degree, positive coefficient

Describe both ends of the graph using words or arrow notation.

Left end rises; right end rises...

Your turn

Question 1

State the end behaviour using words or arrow notation.

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Question 2

State the end behaviour using words or arrow notation.

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Question 3

State the end behaviour using words or arrow notation.

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Question 4

State the end behaviour using words or arrow notation.

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Question 5

State the end behaviour using words or arrow notation.

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