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3 years ago

the scale on a road map indicates that 2 inches equal 30 miles how many inches would represent 120 miles on this road map?

Mathematics

2 answers:

shtirl [24]3 years ago

7 0

It would be 6 inches

Natasha_Volkova [10]3 years ago

6 0

Answer:

Its actually 8

Step-by-step explanation:

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In order to tell if a graph is a function it must

nikitadnepr [17]

You can use the vertical line test (the blue lines on the drawing) and if the other end or if any part of the line touches the blue line, then it isn’t a function.

5 0

3 years ago

Evaluate the integral, show all steps please!

Aloiza [94]

Answer:

$\displaystyle \int \dfrac{1}{(9-x^2)^{\frac{3}{2}}}\:\:\text{d}x=\dfrac{x}{9\sqrt{9-x^2}} +\text{C}$

Step-by-step explanation:

<u>Fundamental Theorem of Calculus</u>

$\displaystyle \int \text{f}(x)\:\text{d}x=\text{F}(x)+\text{C} \iff \text{f}(x)=\dfrac{\text{d}}{\text{d}x}(\text{F}(x))$

If differentiating takes you from one function to another, then integrating the second function will take you back to the first with a constant of integration.

Given indefinite integral:

$\displaystyle \int \dfrac{1}{(9-x^2)^{\frac{3}{2}}}\:\:\text{d}x$

Rewrite 9 as 3² and rewrite the 3/2 exponent as square root to the power of 3:

$\implies \displaystyle \int \dfrac{1}{\left(\sqrt{3^2-x^2}\right)^3}\:\:\text{d}x$

<u>Integration by substitution</u>

<u />

<u /> $\boxed{\textsf{For }\sqrt{a^2-x^2} \textsf{ use the substitution }x=a \sin \theta}$

$\textsf{Let }x=3 \sin \theta$

$\begin{aligned}\implies \sqrt{3^2-x^2} & =\sqrt{3^2-(3 \sin \theta)^2}\\ & = \sqrt{9-9 \sin^2 \theta}\\ & = \sqrt{9(1-\sin^2 \theta)}\\ & = \sqrt{9 \cos^2 \theta}\\ & = 3 \cos \theta\end{aligned}$

Find the derivative of x and rewrite it so that dx is on its own:

$\implies \dfrac{\text{d}x}{\text{d}\theta}=3 \cos \theta$

$\implies \text{d}x=3 \cos \theta\:\:\text{d}\theta$

<u>Substitute</u> everything into the original integral:

$\begin{aligned}\displaystyle \int \dfrac{1}{(9-x^2)^{\frac{3}{2}}}\:\:\text{d}x & = \int \dfrac{1}{\left(\sqrt{3^2-x^2}\right)^3}\:\:\text{d}x\\\\& = \int \dfrac{1}{\left(3 \cos \theta\right)^3}\:\:3 \cos \theta\:\:\text{d}\theta \\\\ & = \int \dfrac{1}{\left(3 \cos \theta\right)^2}\:\:\text{d}\theta \\\\ & = \int \dfrac{1}{9 \cos^2 \theta} \:\: \text{d}\theta\end{aligned}$

Take out the constant:

$\implies \displaystyle \dfrac{1}{9} \int \dfrac{1}{\cos^2 \theta}\:\:\text{d}\theta$

$\textsf{Use the trigonometric identity}: \quad\sec^2 \theta=\dfrac{1}{\cos^2 \theta}$

$\implies \displaystyle \dfrac{1}{9} \int \sec^2 \theta\:\:\text{d}\theta$

$\boxed{\begin{minipage}{5 cm}\underline{Integrating $\sec^2 kx$}\\\\$\displaystyle \int \sec^2 kx\:\text{d}x=\dfrac{1}{k} \tan kx\:\:(+\text{C})$\end{minipage}}$

$\implies \displaystyle \dfrac{1}{9} \int \sec^2 \theta\:\:\text{d}\theta = \dfrac{1}{9} \tan \theta+\text{C}$

$\textsf{Use the trigonometric identity}: \quad \tan \theta=\dfrac{\sin \theta}{\cos \theta}$

$\implies \dfrac{\sin \theta}{9 \cos \theta} +\text{C}$

$\textsf{Substitute back in } \sin \theta=\dfrac{x}{3}:$

$\implies \dfrac{x}{9(3 \cos \theta)} +\text{C}$

$\textsf{Substitute back in }3 \cos \theta=\sqrt{9-x^2}:$

$\implies \dfrac{x}{9\sqrt{9-x^2}} +\text{C}$

Learn more about integration by substitution here:

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4 0

2 years ago

The pharmacist uses 67mg, 100g and 0.6 kg of drug to compound 3 separate precription. how much total drug did the pharmacist use

FromTheMoon [43]

Answer: 700.067 g

Step-by-step explanation:

Given : The pharmacist uses 67mg, 100g and 0.6 kg of drug to compound 3 separate prescription.

We know that 1 gram= 1000 milligram

and 1 kilogram = 1000 grams

Then, By UNITARY METHOD, $\text{1 mg}=\dfrac{1}{1000}\text{ gram}$

Now, We convert each amount of drug into grams as ,

$67\ mg=67\times\dfrac{1}{1000}\ g\\\\=0.067\text{ g}$

AND

$0.6\ kg=0.6\times100=60\text{ g}$

Now, the total drug used by Pharmacist (in grams) = $0.067+100+600=700.067\ g$

Hence, Pharmacist used 700.067 g of total drug.

8 0

3 years ago

What are the coordinates of the vertex of the graph of the absolute value function h(x) = 3|x + 5| + 2? A) (5,-2) B) (-5,2) C) (

saw5 [17]

Answer:

B) Vertex = (-5, 2)

Step-by-step explanation:

Vertex can be defined as defined as the point where two lines meet and form a particular angle with each other. It can also be described as the point where a line changes its direction

We can find vertex by two methods:

<h3>1) GRAPH</h3>

We can see in the graph attached below that the line changes its direction at point (-5, 2). So the vertex is (-5,2)

<h3>2) FORMULA</h3>

General form of equation of mod function is given by

y = a |x - h| + k

where Vertex = (h, k)

The given equation is

h(x) = 3 |x + 5| + 2

h(x) = 3 |x - (-5)| + 2

where h = -5 and k = 2

So the vertex is:

Vertex = (-5, 2)

7 0

4 years ago

Can I have the answer

harkovskaia [24]

Answer:

to what?

Step-by-step explanation:

7 0

3 years ago