What is cos 0 when sin 0 = 2/5

igomit [66]

For f(x)=1/x^2-3

Find

A) f(3)

B) f(2-h)

If f(x)=1/x^2-3, then f(3) = 1 / 3^2 - 3. The exponentiation here must be carried out first: f(3) = 1/9 - 3. Then f(3) = 1/9 - 27/9 = -26/9

If f(x)=1/x^2-3, then f(2-h) = 1 / [2-h]^2 - 3. This result may be left as is or expanded. In expanded form, we have:

1

f(2-h) = ------------------ - 3

4-4h +h^2

5 0

3 years ago

A random sample of 85 sixth-graders in a large city take a course designed to improve scores on a reading comprehension test. Ba

BartSMP [9]

Answer:

$12.6 < \mu < 14.8$

For this case we can find the margin of error like this:

$ME= \frac{14.8-12.6}{2}= 1.1$

Since we need to divide the width of the interval by 2.

And now with the margin of error we can find the sample mean with any of the two following ways:

$12.6 +1.1=13.7$

$14.8-1.1=13.7$

So for this case the correct answer would be:

A. Sample Mean = 13.7; Margin of Error = 1.1

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

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".

Solution to the problem

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=85-1=84$

We know that the confidence interval is given by:

$12.6 < \mu < 14.8$

For this case we can find the margin of error like this:

$ME= \frac{14.8-12.6}{2}= 1.1$

Since we need to divide the width of the interval by 2.

And now with the margin of error we can find the sample mean with any of the two following ways:

$12.6 +1.1=13.7$

$14.8-1.1=13.7$

So for this case the correct answer would be:

A. Sample Mean = 13.7; Margin of Error = 1.1

3 0

3 years ago

Simplify the expression-3(b-7)

oee [108]

-3(b - 7)

Multiply -3 into the parenthesis.

= -3b + 21.

8 0

3 years ago

Read 2 more answers

Please help me with these Algebra Questions!!

Bess [88]

Answer:

There is nothing here!

Step-by-step explanation:

I don't see anything to solve.

: )

3 0

3 years ago

1. An orange is peeled . 18 identical sectors are found . What angle do does each semicircular surface make with another in a wh

KatRina [158]

Answer:

<u>Since the circle covers 360°, each sector will be:</u>

360°/18 = 20°

The same angle will be made between two adjacent semicircles.

The points have same latitude but different longitude.

35°W and 15° are at different sides from zero longitude.

<u>The difference is:</u>

35° + 15° = 50°

8 0

3 years ago