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Sketch the graph
F(x)=3x^4 -4x^3

User Josan
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1 Answer

7 votes

The graph of the polynomial f(x)= 3x⁴ - 4x³ is in the image at the end.

How to sketch the graph of the polynomial?

Here we have the polynomial:

f(x)= 3x⁴ - 4x³

Notice that we can rewrite this polynomial as:

f(x)= x³(3x - 4)

First, notice that when x = 0 we have:

f(0) = 0³*(3*0 - 4) = 0

We have a root here with multiplicity of 3.

Also, when:

(3x - 4) = 0

We have the other root.

3x = 4

x = 4/3

So:

f(4/3) = 0

At the moment we have two roots (0, 0) and (4/3 ,0)

Finally, also we can notice that the degree is even (it is 4), and the leading coefficient is positive (it is 3)

Which means that the end behavior is:

x → ∞, f(x) →∞

x → -∞, f(x) →∞

Sketch the graph F(x)=3x^4 -4x^3-example-1
User Alex Koukoulas
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8.3k points