Answer:
h'(x) = (-x² ln x + x² + 1) / (x (x² + 1)^(³/₂))
Step-by-step explanation:
h(x) = ln x / √(x² + 1)
You can either use quotient rule, or you can rewrite using negative exponents and use product rule.
h(x) = (ln x) (x² + 1)^(-½)
h'(x) = (ln x) (-½) (x² + 1)^(-³/₂) (2x) + (1/x) (x² + 1)^(-½)
h'(x) = (-x ln x) (x² + 1)^(-³/₂) + (1/x) (x² + 1)^(-½)
h'(x) = (x² + 1)^(-³/₂) (-x ln x + (1/x) (x² + 1))
h'(x) = (1/x) (x² + 1)^(-³/₂) (-x² ln x + x² + 1)
h'(x) = (-x² ln x + x² + 1) / (x (x² + 1)^(³/₂))
Answer:
Number of families that should be surveyed if one wants to be 90% sure of being able to estimate the true mean PSLT within 0.5 is at least 43.
Step-by-step explanation:
We are given that one wants to estimate the mean PSLT for the population of all families in New York City with gross incomes in the range $35.000 to $40.000.
If sigma equals 2.0, we have to find that how many families should be surveyed if one wants to be 90% sure of being able to estimate the true mean PSLT within 0.5.
Here, we will use the concept of Margin of error as the statement "true mean PSLT within 0.5" represents the margin of error we want.
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<u>SO, Margin of error formula is given by;</u>
Margin of error =
where,
= significance level = 10%
= standard deviation = 2.0
n = number of families
Now, in the z table the critical value of x at 5% (
) level of significance is 1.645.
SO, Margin of error =
0.5 =

n =
= 43.3 ≈ 43
Therefore, number of families that should be surveyed if one wants to be 90% sure of being able to estimate the true mean PSLT within 0.5 is at least 43.
x + 4 = 12 Subtract 4 on both sides to get "x" by itself
x + 4 - 4 = 12 - 4
x = 8
Answer:
140
Step-by-step explanation:
When working HCF and LCM problems, I like to think in terms of this little diagram:
(a [ b ) c]
It shows me one of the numbers is ab, the other is bc, the HCF is b and the LCM is abc. "a" and "c" must be relatively prime for "b" to be the HCF.
__
Here, we're given ...
b = 20
ab = 320
abc = 2240
Then ...
c = abc/(ab) = 2240/320 = 7
x = bc = 20(7) . . . . . . equivalently, x = (abc·b)/(ab) = (2240·20)/320
x = 140
Is this for area and perimeter? If so, first make the fraction a decimal, (that would be 3.5). Then, for permeter, add 3.5 + 3.5 + 9 + 9, which is 25, for area, multiply 3.5 by 9, which is 31.5. Hope this helped!