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2 years ago

(4₊√₋81)₋(9₊√₋9) i cant resolve this equation. thanks for help

Mathematics

2 answers:

bezimeni [28]2 years ago

8 0

The question can't be solved because we can't have negative sign under square root

gulaghasi [49]2 years ago

3 0

Answer:

-5 +6i

Step-by-step explanation:

Square roots of negative numbers are imaginary. This is asking for the difference of two complex numbers. A suitable calculator can show you what that is.

<h3>simplify radicals</h3>

We know that √(-1) ≜ i. This means the radicals can be simplified to ...

$\sqrt{-81}=\sqrt{9^2(-1)}=9\sqrt{-1}=9i\\\\\sqrt{-9}=\sqrt{3^2(-1)}=3\sqrt{-1}=3i$

So the expression becomes ...

(4 +9i) -(9 +3i)

<h3>combine terms</h3>

Like terms can be combined in the usual way. For the purpose here, i can be treated as though it were a variable.

(4 +9i) -(9 +3i) = 4 +9i -9 -3i

= (4 -9) +(9 -3)i

= -5 +6i

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Answer:

132

Step-by-step explanation:

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Assume the sample variances to be continuous measurements. Find the probability that a random sample of 25observations, from a n

konstantin123 [22]

Answer:

a) $P(4S^2 > 4*9.1) = P(\chi^2_{24} >36.4) = 0.0502$

b) $P(13.848$ Step-by-step explanation:

Previous concepts

The Chi Square distribution is the distribution of the sum of squared standard normal deviates .

For this case we assume that the sample variance is given by $S^2$ and we select a random sample of size n from a normal population with a population variance $\sigma^2$ . And we define the following statistic:

$T = \frac{(n-1) S^2}{\sigma^2}$

And the distribution for this statistic is $T \sim \chi^2_{n-1}$

For this case we know that n =25 and $\sigma^2 = 6$ so then our statistic would be given by:

$\chi^2 = \frac{(n-1)S^2}{\sigma^2}=\frac{24 S^2}{6}= 4S^2$

With 25-1 =24 degrees of freedom.

Solution to the problem

Part a

For this case we want this probability:

$P(S^2 > 9.1)$

And we can multiply the inequality by 4 on both sides and we got:

$P(4S^2 > 4*9.1) = P(\chi^2_{24} >36.4) = 0.0502$

And we can use the following excel code to find it: "=1-CHISQ.DIST(36.4,24,TRUE)"

Part b

For this case we want this probability:

$P(3.462 < S^2$

If we multiply the inequality by 4 on all the terms we got:

$P(3.462*4 < 4S^2 < 4*10.745)= P(13.848< \chi^2$ And we can find this probability like this: $P(13.848$ And we use the following code to find the answer in excel: "=CHISQ.DIST(42.98,24,TRUE)-CHISQ.DIST(13.848,24,TRUE)"

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2 years ago

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Tcecarenko [31]

Answer:

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Step-by-step explanation:

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elixir [45]

Answer:

<u><em>Measure of angle A is 27 7/9 degrees.</em></u>

Step-by-step explanation:

Lets call measure of angle A is <em><u>X-10</u></em>

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2 years ago

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Elanso [62]

Answer:

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