Practice Problems

Answers

  1. All the options have the same linear factors: x,
    (2x-5), and (x+2). This makes sense, as the graph has zeros at x=0x=\dfrac{5}2, and x=-2.

    The difference between the options is in the  of the zeros. To determine which option is correct, we need to think about multiplicity:

    • If the multiplicity of a zero is an odd number, the graph will cross the x-axis at that zero.
    • If the multiplicity of a zero is an even number, the graph will only touch the x-axis at that zero.

    We see that the graph crosses the x-axis at x=-2 and x=\dfrac{5}2. So their multiplicities must be odd numbers.

    We see that the graph touches the x-axis at x=0. So its multiplicity must be an even number.

    In conclusion, this is the correct answer:

    p(x)=x^2(2x-5)(x+2)


  2. All the options have the same linear factors: (x+3), (x+1), and (2x-1). This makes sense, as the graph has zeros at x=-3, x=-1, and x=\dfrac{1}2.

    The difference between the options is in the  of the zeros. To determine which option is correct, we need to think about multiplicity:

    • If the multiplicity of a zero is an odd number, the graph will cross the x-axis at that zero.
    • If the multiplicity of a zero is an even number, the graph will only touch the x-axis at that zero.

    We see that the graph crosses the x-axis at x=-3 and  x=\dfrac{1}2. So their multiplicities must be odd numbers.

    We see that the graph touches the x-axis at x=-1. So its multiplicity must be an even number.

    In conclusion, this is the correct answer:

    p(x)=(x+3)(x+1)^2(2x-1)


  3. All the options have the same linear factors: 2x and (x-2). This makes sense, as the graph has zeros at x=0 and x=2.

    The difference between the options is in the  of the zeros. To determine which option is correct, we need to think about multiplicity:

    • If the multiplicity of a zero is an odd number, the graph will cross the x-axis at that zero.
    • If the multiplicity of a zero is an even number, the graph will only touch the x-axis at that zero.

    We see that the graph crosses the x-axis at x=2. So its multiplicity must be an odd number.

    We see that the graph touches the x-axis at x=0. So its multiplicity must be an even number.

    In conclusion, this is the correct answer:

    p(x)=2x^2(x-2)^3


  4. All the options have the same linear factors: (x-1),
    (2x+7), and (x+1). This makes sense, as the graph has zeros at x=1, x=-\dfrac{7}2, and x=-1.

    The difference between the options is in the  of the zeros. To determine which option is correct, we need to think about multiplicity:

    • If the multiplicity of a zero is an odd number, the graph will cross the x-axis at that zero.
    • If the multiplicity of a zero is an even number, the graph will only touch the x-axis at that zero.

    We see that the graph crosses the x-axis at x=1. So its multiplicity must be an odd number.

    We see that the graph touches the x-axis at x=-\dfrac{7}2 and x=-1. So their multiplicities must be even numbers.

    In conclusion, this is the correct answer:

    p(x)=(x-1)(2x+7)^2(x+1)^2