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BrotherBear
BrotherBear asked in Science & MathematicsMathematics · 9 years ago

If f(2)=2, and f(4)=5, what is x when f(x)=0.?

If f(2)=2, and f(4)=5, what is x when f(x)=0?

I skipped this question.

4 Answers

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  • Ed I
    Lv 7
    9 years ago
    Favorite Answer

    m = (5 - 2)/(4 - 2) = 3/2

    y - 2 = (3/2) (x - 2)

    y - 2 = (3/2) x - 3

    y = (3/2) x - 1 = f(x)

    (3/2) x - 1 = 0

    (3/2) x = 1

    x = 2/3

    I didn't skip this question.

  • MechEng2030
    Lv 7
    9 years ago

    Form an equation of a line from the two points:

    m = (5 - 2)/(4 - 2) = 3/2

    Eqn of line:

    y - 5 = 3/2*(x - 4)

    y = 3x/2 - 1

    f(x) = 0 when x = 2/3

  • Iggy Rocko
    Lv 7
    9 years ago

    Not enough information unless f is linear. Assuming f is linear, the slope of this line is

    (2 - 5)/(2 - 4) = 3/2

    Slope is also

    (f(x) - 2)/(x - 2) = 3/2

    (0 - 2)/(x - 2) = 3/2

    -2/(x - 2) = 3/2

    (x - 2)/(-2) = 2/3

    x - 2 = -4/3

    x = 2/3

  • Anonymous
    9 years ago

    You have left out some of the question!

    If it is linear the previous answer does...

    Suppose f(x)=x^2+bx+c

    which is a perfectly good function

    then 4+2b+c=2

    and 16+4b+c=5

    Solve for b and c

    So f(0)=c

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