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3 years ago

Which of the following is a factor of f(x) = 3x3 + 8x2 − 87x + 28?

Mathematics

2 answers:

Gennadij [26K]3 years ago

6 0

Answer with explanation:

The expression whose factor we have to find is

$f(x) = 3x^3 + 8x^2 - 87x + 28\\\\f(x)=3*[x^3+\frac{8x^2}{3}-29x+\frac{28}{3}]\\\\\text{By rational root test possible roots are}\\\\ \pm 1, \pm 2, \pm 4,\pm 7,\pm \frac{1}{3},\pm \frac{2}{3},\pm \frac{4}{3},\pm \frac{7}{3},\pm 28.$

First two options are rejected as the expression can,t have factor $\pm\frac{1}{4}$ .

$f(4)=3*4^3+8*4^2-87*4+28\\\\f(4)=192+128-348+28\\\\f(4)=348-348\\\\f(4)=0\\\\f(-4)=3*(-4)^3+8*(-4)^2-87*(-4)+28\\\\f(4)=-192+128+348+28\\\\f(4)\neq 0$

So, root of the expression is , x=4.

Option C: x-4

Mumz [18]3 years ago

3 0

The answer should be (x-4)

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2 years ago

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$98\% \ C. \ I.=\bar{x}\pm z_{\alpha/2}\left(\frac{\sigma}{\sqrt{n}}\right) \\ \\ =10.0023\pm2.33\left(\frac{0.0002}{\sqrt{5}}\right) \\ \\ =10.0023\pm2.33(0.000089) \\ \\ =10.0023\pm0.00021 \\ \\ =(10.0023-0.00021, \ 10.0023+0.00021) \\ \\ =(10.0021, \ 10.0025)$

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The probability that a randomly chosen person has measles antibodies in his/her blood if the new test is positive = 0.9796

Step-by-step explanation:

The event that someone tests positive = P(T)

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The probability that a randomly chosen person has measles antibodies in his/her blood if the new test is positive = P(A|T)

This conditional probability is given as

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