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2 years ago

The value of 2(cos square 45 + tan square 60) is

Mathematics

1 answer:

Sergeu [11.5K]2 years ago

7 0

Answer:

Step-by-step explanation:

Using the exact values for

cos45° = $\frac{1}{\sqrt{2} }$ and tan60° = $\sqrt{3}$ , then

2(cos²45° + tan²60°)

= 2( ( $\frac{1}{\sqrt{2} }$ )² + ( $\sqrt{3}$ )² )

= 2( $\frac{1}{2}$ + 3 ) ← distribute

= 1 + 6

= 7

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A study was designed to investigate the effects of two variables, (1) A student's level of mathematical anxiety and (2) teach

Mashcka [7]

Answer:

$P(X>400)=P(\frac{X-\mu}{\sigma}>\frac{400-\mu}{\sigma})=P(Z>\frac{400-440}{20})=P(z>-2)$

And we can find this probability using the complement rule:

$P(z>-2)=1-P(z$

And in order to find these probabilities we can find tables for the normal standard distribution, excel or a calculator.

$P(z>-2)=1-P(z$

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Solution to the problem

Let X the random variable that represent the scores of a population, and for this case we know the distribution for X is given by:

$X \sim N(440,20)$

Where $\mu=440$ and $\sigma=20$

We are interested on this probability

$P(X>440)$

And the best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{x-\mu}{\sigma}$

If we apply this formula to our probability we got this:

$P(X>400)=P(\frac{X-\mu}{\sigma}>\frac{400-\mu}{\sigma})=P(Z>\frac{400-440}{20})=P(z>-2)$

And we can find this probability using the complement rule:

$P(z>-2)=1-P(z$

And in order to find these probabilities we can find tables for the normal standard distribution, excel or a calculator.

$P(z>-2)=1-P(z$

6 0

3 years ago

Which sample fairly represents the population? Select two options.

ExtremeBDS [4]

Answer:

b) observing every person walking down Main Street at 5 p.m. one evening to determine the percentage of people who wear glasses.

d) taking a poll in the lunch room (where all students currently have to eat lunch) to determine the number of students who want to be able to leave campus during lunch.

Step-by-step explanation:

These are the two options that are most likely to give you a sample that fairly represents the population. In the first case, the sample that you obtain is likely to be a good representation because Main Street is a road where a great variety of people walk. Moreover, 5 pm is also a time that will allow you to see a great number of different people. The second answer will also give you a good sample, as the poll would include all students in the lunch room, which is all students in the school (the whole population).

7 0

3 years ago

Read 2 more answers

Solve the equation

kondor19780726 [428]

4 1/5 + B = 9 3/5

21/5 + B = 48/5

B = 27/5

B = 5 2/5

Letter C is the correct answer!

Hope this helps! ;)

4 0

3 years ago

The weight of a full steel bead tire is approximately 800 grams, while a lighter wheel weighs only 700 grams. What is the weight

SIZIF [17.4K]

800= about 1.76 lbs

700= about 1.54 lbs

(there are about 453.5 grams in a pound

4 0

3 years ago

Read 2 more answers

Without

aivan3 [116]

Answer:

Thousandths place.

Step-by-step explanation:

The answer doesn't change that drastically

6 0

2 years ago