Find (if possible) the rational zeros of the function. (Enter your answers as a comma-separated list. If an answer does not exist, enter DNE.) f(x)=4x3−34x2+80x−32
Q. Find (if possible) the rational zeros of the function. (Enter your answers as a comma-separated list. If an answer does not exist, enter DNE.) f(x)=4x3−34x2+80x−32
Apply Rational Root Theorem: To find the rational zeros of the polynomial, we can use the Rational Root Theorem, which states that any rational zero, expressed in its lowest terms qp, is such that p is a factor of the constant term and q is a factor of the leading coefficient.
List Factors: First, we list the factors of the constant term (−32) and the leading coefficient (4).Factors of −32: ±1, ±2, ±4, ±8, ±16, ±32Factors of 4: ±1, ±2, ±4
Form Possible Fractions: Now, we form all possible fractionsqp using the factors of −32 for p and the factors of 4 for q. We simplify them if necessary to get all possible rational zeros.Possible rational zeros: ±1, ±21, ±41, ±2, ±42 (which simplifies to ±21), −321, −322 (which simplifies to ±1), −324, −325 (which simplifies to ±2), −327, −328 (which simplifies to −321), p0, p1 (which simplifies to −324)
Test Rational Zeros: We test each possible rational zero by substituting it into the polynomial f(x) and checking if it results in zero. This can be done using synthetic division or direct substitution.
Test x=1: Let's start by testing x=1:f(1)=4(1)3−34(1)2+80(1)−32=4−34+80−32=18Since f(1)=0, x=1 is not a zero.
Test x=−1: Next, we test x=−1: f(−1)=4(−1)3−34(−1)2+80(−1)−32=−4−34−80−32=−150 Since f(−1)=0, x=−1 is not a zero.
Test Remaining Zeros: We continue testing the remaining possible rational zeros. After testing all of them, we find that x=2 is a zero: f(2)=4(2)3−34(2)2+80(2)−32=32−136+160−32=24 This is incorrect, as f(2)=0, so x=2 is not a zero.
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