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2 years ago

Please solve this and only answer with image

Mathematics

1 answer:

horsena [70]2 years ago

5 0

$\cot^4 A - \cot^2 A = 1\\\\\cot^4 A = 1 + \cot^2 A\\\\\frac{\cos^4 A}{\sin^4 A} = 1 + \frac{\cos^2 A}{\sin^2 A}\\\\\frac{\cos^4 A}{\sin^4 A} = \frac{\sin^2 A}{\sin^2 A}+\frac{\cos^2 A}{\sin^2 A}\\\\\frac{\cos^4 A}{\sin^4 A} = \frac{\sin^2 A+\cos^2 A}{\sin^2 A}\\\\\frac{\cos^4 A}{\sin^4 A} = \frac{1}{\sin^2 A}\\\\\cos^4 A = \frac{\sin^4 A}{\sin^2 A}\\\\\cos^4 A = \sin^2 A\\\\$

This then means,

$\cos^4 A + \cos^2 A = 1\\\\\sin^2 A + \cos^2 A = 1\\\\$

which is the pythagorean trig identity. This concludes the proof.

Therefore, if $\cot^4 A - \cot^2 A = 1$ , then $\cos^4 A + \cos^2 A = 1$

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The 10th term of an a.p is -27 and the 5th term is -12 .find the first term?

horsena [70]

Step-by-step explanation:

$a_{10} = - 27... (Given) \\\\\therefore a + 9d = - 27...... (1)\\\\a_{5} = - 12... (Given) \\\\\therefore a + 4d = - 12.......(2)\\\\$

Subtracting equation (2) from equation (1)

$a + 9d-( a + 4d )= - 27-(-12)\\\\\therefore a +9d - a-4d = - 27+12\\\\\therefore 5d = - 15\\\\\therefore d = \frac {- 15}{5}\\\\\huge \orange {\boxed {\therefore d = -3}} \\\\$

Substituting d = - 3 in equation (1), we find:

$a + 9\times (-3)= - 27\\\\\therefore a - 27 = - 27\\\\\therefore a = 27- 27\\\\\huge \red {\boxed {\therefore a = 0}}\\\\$

Hence, first term is zero.

3 0

3 years ago

Write 10 1/2 as a decimal number

VikaD [51]

Answer:

10.5

Step-by-step explanation:

1/2 as a decimal is 0.5

so 10 is a whole number so i dont have to change it.

then answer is 10.5

7 0

3 years ago

Read 2 more answers

In a parallelogram, if the measure of y is 32 degrees what is the measure of w

alekssr [168]

Talking about a parallelogram, we know that:
opposite sides and angles are congruent
in the picture below:
∠A = ∠C
AD = BC
if one angle is right, then the rest are right as well (making it a rectangle/square)
The consecutive angles are supplementary (meaning they add up to 180)
A + D = 180°

If y and w are consecutive angles, then
w = 180 - 32
=148°
If they are opposite angles, w = 32° (congruent angles)

8 0

3 years ago

In 2002, the mean age of an inmate on death row was 40.7 years with a standard deviation of 9.6 years according to the U.S. Depa

marissa [1.9K]

Answer:

The 95% confidence interval for the current mean age of death-row inmates is between 42.23 years and 35.57 years.

Step-by-step explanation:

The confidence interval of the mean is given by the next formula:

$\\ \overline{x} \pm z_{1-\frac{\alpha}{2}}\frac{\sigma}{\sqrt{n}}$ [1]

We already know (according to the U.S. Department of Justice):

The (population) standard deviation for this case (mean age of an inmate on death row) has a standard deviation of 9.6 years ( $\\ \sigma = 9.6$ years).
The number of observations for the sample taken is $\\ n = 32$ .
The sample mean, $\\ \overline{x} = 38.9$ years.

For $\\ z_{1-\frac{\alpha}{2}}$ , we have that $\\ \alpha = 0.05$ . That is, the level of significance $\\ \alpha$ is 1 - 0.95 = 0.05. In this case, then, we have that the z-score corresponding to this case is:

$\\ z_{1-\frac{\alpha}{2}} = z_{1-\frac{0.05}{2}} = z_{1-0.025} = z_{0.975}$

Consulting a cumulative standard normal table, available on the Internet or in Statistics books, to find the z-score associated to the probability of, $\\ P(z$ , we have that $\\ z = 1.96$ .

Notice that we supposed that the sample is from a population that follows a normal distribution. However, we also have a value for n > 30, and we already know that for this result the sampling distribution for the sample means follows, approximately, a normal distribution with mean, $\\ \mu$ , and standard deviation, $\\ \sigma_{\overline{x}} = \frac{\sigma}{\sqrt{n}}$ .

Having all this information, we can proceed to answer the question.

Constructing the 95% confidence interval for the current mean age of death-row inmates

To construct the 95% confidence interval, we already know that this interval is given by [1]:

$\\ \overline{x} \pm z_{1-\frac{\alpha}{2}}\frac{\sigma}{\sqrt{n}}$

That is, we have:

$\\ \overline{x} = 38.9$ years.

$\\ z_{1-\frac{\alpha}{2}} = 1.96$

$\\ \sigma = 9.6$ years.

$\\ n = 32$

Then

$\\ 38.9 \pm 1.96*\frac{9.6}{\sqrt{32}}$

$\\ 38.9 \pm 1.96*\frac{9.6}{5.656854}$

$\\ 38.9 \pm 1.96*1.697056$

$\\ 38.9 \pm 3.326229$

Therefore, the Upper and Lower limits of the interval are:

Upper limit:

$\\ 38.9 + 3.326229$

$\\ 42.226229 \approx 42.23$ years.

Lower limit:

$\\ 38.9 - 3.326229$

$\\ 35.573771 \approx 35.57$ years.

In sum, the 95% confidence interval for the current mean age of death-row inmates is between 42.23 years and 35.57 years.

Notice that the "mean age of an inmate on death row was 40.7 years in 2002", and this value is between the limits of the 95% confidence interval obtained. So, according to the random sample under study, it seems that this mean age has not changed.

7 0

3 years ago

Smith has a dairy farm in which the number of cows increases at the rate of 5% per annum which results in the increase in the pr

marshall27 [118]

Answer:

d. 194481

Step-by-step explanation:

We solve this question using exponential growth rate formula

This is given as:

y = a(1 + r) ^t

Where y = Amount after time t

a = Initial amount = 160000

r = growth or increase rate = 5% = 0.05

t = time in years = 4

y = 160000(1 + 0.05)⁴

y = 160000(1.05)⁴

y = 194481

Therefore, the number of cows needed after 4 years to fulfill the requirement of the milk is 194481

7 0

2 years ago