All courses Math III · F-IF.7.c 25 of 55
Graph polynomial functions using zeros, factorizations, and end behavior.

Inventory polynomial graph features from factored form

Problem
For f(x)=(x-2)(x+1)², enter one row per real zero with multiplicity/parity/cross-or-touch behavior, then degree, leading coefficient, y-intercept, and separate left/right end limits.
Your answer
Choose an answer
With a free account

Share practice with a session code.

Every learning session has a code, making it easy to share the same included practice with someone else.

Create a free account
With paid access

Try the same skill with new numbers.

More variants let you check whether you understand the method instead of remembering one answer.

Compare plans

Hint

List factor equations and exponents before computing degree and leading coefficient.

Each factor gives a zero and multiplicity; odd multiplicity crosses, even touches. Use the leading term for end behavior and f(0) for y-intercept.

Solution walkthrough

01

Find the zeros

\[x-2~=~0\Rightarrow~x~=~2\qquad~x+1~=~0\Rightarrow~x~=~-1\]

The factored form shows the x-intercepts directly.

02

Use multiplicity for intercept behavior

\[(x-2)^1\Rightarrow~\text{crosses at }2\qquad~(x+1)^2\Rightarrow~\text{touches at }-1\]

Multiplicity \(1\) gives a crossing, while multiplicity \(2\) gives touch-and-turn behavior.

03

Determine the end behavior

\[\text{degree }3~\text{ with positive leading coefficient}\]

A positive cubic falls to the left and rises to the right.

04

State the key graph features

\[\text{zero}~\text{rows}=(x=2,\text{multiplicity}~1,\text{odd},\text{crosses});(x=-1,\text{multiplicity}~2,\text{even},\text{touches});~\text{degree}=3;~\text{leading}~\text{coefficient}=1;~y-\text{intercept}=(0,-2);~\text{left}~\text{end}~\text{as}~x→-∞,f(x)→-∞;~\text{right}~\text{end}~\text{as}~x→∞,f(x)→∞\]

These features tell you how the graph should look at its intercepts and at both ends.

+

Another way

  1. You can compare the end behavior to \(x^3\) first, then add the touch-versus-cross behavior from the factors.

!

Common mistake

A common mistake is to say the graph crosses at \(x=-1\), but the squared factor means the graph touches and turns there.

Answer polynomial graph touching at x equals negative 1, crossing at x equals 2, and passing through (0,negative 2), with left-down right-up tails.
degree 3, leading coefficient 1 left down; right up