Directions: Using trig functions, find the value of each variable. Write your final answer

Evaluate: 5 - 3 x when x = - 7

tamaranim1 [39]

5 - 3 x
= 5 - 3 (-7)
= 5 + 21
= 26

3 0

3 years ago

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Please help i suck at math

Travka [436]

Answer:

7 i think

Step-by-step explanation:

5 0

2 years ago

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If a radius of a circle bisects a chord which is not a diameter, then ______

elena-14-01-66 [18.8K]

Frst, some notation. Let AB be a chord on circle O, and let CD be a diameter of O that passes through AB at M.

4 0

2 years ago

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For some transformation having kinetics that obey the Avrami equation (Equation 10.17), the parameter n is known to have a value

Nikolay [14]

Given Information:

constant = n = 1.7

transformation time 50% completion = t₅₀ = 100 s

Required Information:

transformation time 99% completion = t₉₀ = ?

Answer:

transformation time 99% completion = $t_{90} = 202.75$ $seconds$

Step-by-step explanation:

The Avrami equation is used to model the transformation of solids that is from one phase to another provided that temperature is constant.

The equation is given by

$y=1 - e^{{-kt}^{n}}$

Where t is the transformation time in seconds and n, k are constants.

Let us first find the constant k, since after 100 s transformation is 50% complete,

$0.50=1 - e^{{-k*100}^{1.7}}$

$0.50 - 1= - e^{{-k*100}^{1.7}}$

$-0.50= - e^{{-k*100}^{1.7}}$

$0.50 = e^{{-k*100}^{1.7}}$

Take ln on both sides,

$ln(0.50) = ln(e^{{-k*100}^{1.7}})$

$-0.693 = -k*100}^{1.7}$

$0.693 = k*100}^{1.7}$

$k = 0.693/100}^{1.7}$

$k = 2.759*10^{-4}$

Now we can find out the time when the transformation is 99% complete.

$0.90=1 - e^{{-kt}^{n}}$

$0.90 - 1= - e^{{-k*t}^{n}}$

$-0.10= - e^{{-kt}^{n}}$

$0.10 = e^{{-kt}^{n}}$

Take ln on both sides,

$ln(0.10) = ln(e^{{-k*t}^{n}})$

$-2.303 = -kt}^{n}$

$\frac{2.303}{k} = t^{n}$

$\frac{2.303}{2.759*10^{-4} } = t^{n}$

Again take ln on both sides

$ln(\frac{2.303}{2.759*10^{-4} }) =ln( t^{n})$

$9.03 = nln(t)$

$\frac{9.03}{n} = ln(t)$

$\frac{9.03}{1.7} = ln(t)$

$5.312 = ln(t)$

Take exponential on both sides

$e^{5.312} = e^{ln(t)}$

$202.75 = t$

$t = 202.75$ $seconds$

8 0

3 years ago

Imagine that a researcher conducts a two-tailed z test with an alpha level of 0.05 (i.e., 5%). The researcher expects to find th

Kaylis [27]

Answer:

Null hypothesis : $\mu_1 = \mu_2$

Alternative hypothesis: $\mu_1 \neq \mu_2$

Or equivalently:

Null hypothesis : $\mu_1 -\mu_2 =0$

Alternative hypothesis: $\mu_1 - \mu_2 \neq 0$

Other important thing is that on the alternative hypothesis we never can have the symbol equal.

Step-by-step explanation:

Some previous concepts

A hypothesis is defined as "a speculation or theory based on insufficient evidence that lends itself to further testing and experimentation. With further testing, a hypothesis can usually be proven true or false".

The null hypothesis is defined as "a hypothesis that says there is no statistical significance between the two variables in the hypothesis. It is the hypothesis that the researcher is trying to disprove".

The alternative hypothesis is "just the inverse, or opposite, of the null hypothesis. It is the hypothesis that researcher is trying to prove".

On this case the she wants to proof if that she samples from will differ from her comparison population. So this needs to be on the alternative hypothesis. And the complement of the alternative hypothesis would be on the null hypothesis.

Solution to the problem

So then she needs to conduct a two tailed z test. Let's assume that the population 1 is the population of interest and the population 2 is the comparison population so then the systam of hypothesis are:

Null hypothesis : $\mu_1 = \mu_2$

Alternative hypothesis: $\mu_1 \neq \mu_2$

Or equivalently:

Null hypothesis : $\mu_1 -\mu_2 =0$

Alternative hypothesis: $\mu_1 - \mu_2 \neq 0$

Other important thing is that on the alternative hypothesis we never can have the symbol equal.

4 0

2 years ago