SOLUTION: Please help me solve this equation Use the intermediate value theorem to determine whether the polynomial function has a zero in the given interval. f(x) = -2x^4 + 2x^2 + 4; [-2,

Algebra ->  Rational-functions -> SOLUTION: Please help me solve this equation Use the intermediate value theorem to determine whether the polynomial function has a zero in the given interval. f(x) = -2x^4 + 2x^2 + 4; [-2,      Log On


   



Question 1048058: Please help me solve this equation
Use the intermediate value theorem to determine whether the polynomial function has a zero in the given interval.
f(x) = -2x^4 + 2x^2 + 4; [-2, -1]

Answer by rothauserc(4718) About Me  (Show Source):
You can put this solution on YOUR website!
f(x) = -2x^4 + 2x^2 + 4; [-2, -1]
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f(-2) = -2(-2)^4 + 2(-2)^2 + 4 = -20
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f(-1) = -2(-1)^4 + 2(-1)^2 + 4 = 4
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at f(-2) the function is below the x axis and at f(-1) the function is above the x axis
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f(x) is continuous since it is a polynomial, this means that f(x) crosses the x axis
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f(x) crossing the x axis means that f(x) has a zero in [-2, -1]
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