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3 years ago

(1) What is the circumference of a circle that has a radius of 3cm ?

Mathematics

1 answer:

erik [133]3 years ago

5 0

Answer:

1. 6 cm

2. 34.6 cm

Step-by-step explanation:

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WARRIOR [948]

Answer:

$2\,(x-1)^2=4$

which is the first option in the list of possible answers.

Step-by-step explanation:

Recall that the minimum of a parabola generated by a quadratic expression is at the vertex of the parabola, and the formula for the vertex of a quadratic of the general form:

$y=ax^2+bx+c$

is at $x_{vertex}=\frac{-b}{2\,a}$

For our case, where $a=2\,\,, b=-4\,\,,\,\,and \,\,c=-2$ we have:

$x_{vertex}=\frac{-b}{2\,a}\\x_{vertex}=\frac{4}{2\,*\,2}\\x_{vertex}=1$

And when x = 1, the value of "y" is:

$y(x)=2x^2-4x-2\\y(1)=2(1)^2-4(1)-2\\y(1)=2-6\\y(1)=-4\\y_{vertex}=-4$

Recall now that we can write the quadratic in what is called: "vertex form" using the coordinates $(x_{vertex},y_{vertex)$ of the vertex as follows:

$y-y_{vertex}=a\,(x-x_{vertex})^2$

Then, for our case:

$y-(-4)=2\,(x-1)^2\\y=2\,(x-1)^2-4$

Then, for the quadratic equal to zero as requested in the problem, we have:

$y=2\,(x-1)^2-4=0\\2\,(x-1)^2-4=0\\2\,(x-1)^2=4$

5 0

3 years ago

Is 4 to 7 the same as 7 to 4? Explain why or why not

Pavlova-9 [17]

Yes

Step-by-step explanation:
4×7=28
and 7×4 also equal to 28

8 0

3 years ago

If the cost of a 2.5 meter cloth is $30.5. What will be the cost of 22 meters ?

alisha [4.7K]

Answer:

268.40

Step-by-step explanation:

We can write a ratio to solve

2.5 meters 22 meters

----------------- = --------------

30.5 dollars x dollars

Using cross products

2.5 * x = 30.5 * 22

2.5x =671

Divide each side by 2.5

2.5x / 2.5 = 671/2.5

x =268.4

8 0

2 years ago

I know that real numbers consist of the natural or counting numbers, whole numbers, integers, rational numbers and irrational nu

ra1l [238]

The imaginary unit $i$ belongs to the set of complex numbers, denoted by $\mathbb C$ . These numbers take the form $a+bi$ , where $a,b$ are any real numbers.

The set of real numbers, $\mathbb R$ , is a subset of $\mathbb C$ , where each number in $\mathbb R$ can be obtained by taking $b=0$ and letting $a$ be any real number.

But any number in $\mathbb C$ with non-zero imaginary part is not a real number. This includes $i$ .

"is it possible that i can use an imaginary number for a real number"

I'm not sure what you mean by this part of your question. It is possible to represent any real number as a complex number, but not a purely imaginary one. All real numbers are complex, but not all complex numbers are real. For example, 2 is real and complex because $2=2+0i$ .

There are some operations that you can carry out on purely imaginary numbers to get a purely real number. A famous example is raising $i$ to the $i$ -th power. Since $i=e^{i\pi/2}$ , we have

$i^i=\left(e^{i\pi/2}\right)^i=e^{i^2\pi/2}=e^{-\pi/2}\approx0.2079$

3 0

3 years ago

Jack wrote this expression to describe how much he will pay for flowers.

kap26 [50]

C

5 x f

5 = price for flowers
f = variable = how many flowers.

3 0

2 years ago

Read 2 more answers