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Find all zer0s of f(x) = 4x^3+44x^2+152x+160

User Loliki
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Answer:

To find the zeros of the function f(x) = 4x^3+44x^2+152x+160, we can use one of several methods. One possible method is as follows:

Step 1: Factor out the common factor 4 from all terms:

f(x) = 4(x^3+11x^2+38x+40)

Step 2: Use the rational root theorem to find possible rational zeros. The rational root theorem states that any rational zero of a polynomial with integer coefficients can be written as a fraction p/q, where p is a factor of the constant term (in this case, 40) and q is a factor of the leading coefficient (in this case, 4).

The factors of 40 are ±1, ±2, ±4, ±5, ±8, ±10, ±20, and ±40.

The factors of 4 are ±1 and ±2.

Therefore, the possible rational zeros are:

±1/4, ±1/2, ±1, ±2, ±4, ±5/2, ±10, and ±20.

Step 3: Test each possible rational zero using synthetic division, until a zero is found. For example, using synthetic division with a possible zero of -4, we get:

-4 | 4 44 152 160

| -16 -112 -160

-----------------

4 28 40 0

Since the remainder is zero, -4 is a zero of f(x), and we have successfully factored f(x) as:

f(x) = 4(x+4)(x^2+7x+10)

Step 4: Solve for the remaining zeros of the quadratic factor x^2+7x+10 using the quadratic formula:

x = [-b ± sqrt(b^2-4ac)] / 2a

= [-7 ± sqrt(7^2-4(1)(10))] / 2

= (-7 ± 3) / 2

Therefore, the zeros of f(x) are:

x = -4, -5, -2

User Max Yaffe
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