All categories

3 years ago

What is the domain of y = 3cos(x)?

Mathematics

1 answer:

Nady [450]3 years ago

4 0

the domain is the values we can input for x

the domain is all real values

{-inf, inf} where inf=infinity

You might be interested in

QUICKK EXPERTS/ACE OR ANYONE WHO WANTS TO HELP!!

olya-2409 [2.1K]

Well since the slope is 4/3 the intercept is -5/3 the point would be on 0,-1.67

6 0

3 years ago

Scores on the Critical Reading part of the SAT exam in a recent year were roughly Normal with mean 495 and standard deviation 11

Karolina [17]

Answer:

Step-by-step explanation:

We use the central limit theorem to solve this question.

The Central Limit Theorem estabilishes that, for a random variable X, with mean $\mu$ and standard deviation $\sigma$ , a large sample size can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$

In this problem, we have that:

$\sigma = 118, n = 100$

$s = \frac{118}{\sqrt{100}} = 11.8$

So the correct answer is:

8 0

3 years ago

The measures of the legs of a right triangle are 15 m and 20 m. What is the length of the hypotenuse?

Alex73 [517]

Use Pythagorean theorem.
15^2+20^2=c^2
225+400=c^2
√655=c
c=25
Answer: D.) 25 m

8 0

4 years ago

Of 1000 randomly selected cases of lung cancer, 823 resulted in death within 10 years.

Arada [10]

Answer:

a) $0.823 - 1.96\sqrt{\frac{0.823(1-0.823)}{1000}}=0.799$

$0.823 + 1.96\sqrt{\frac{0.823(1-0.823)}{1000}}=0.847$

The 95% confidence interval would be given by (0.799;0.847)

b) $n=\frac{0.823(1-0.823)}{(\frac{0.03}{1.96})^2}=621.79$

And rounded up we have that n=622

c) $n=\frac{0.5(1-0.5)}{(\frac{0.03}{1.96})^2}=1067.11$

And rounded up we have that n=1068

Step-by-step explanation:

Part a

$\hat p=\frac{823}{1000}=0.823$

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 95% of confidence, our significance level would be given by $\alpha=1-0.95=0.05$ and $\alpha/2 =0.025$ . And the critical value would be given by: