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4 years ago

Simon does some shopping on the Internet he buys 4cds at 7.39 each

Mathematics

2 answers:

Alexxx [7]4 years ago

6 0

He spent a total of 29.56

Alex787 [66]4 years ago

6 0

7.39 x 4= 29.56
1cd=7.39
you multiply how many there are by how much each one cost

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Convert from rectangular to polar coordinates: note: choose rr and θθ such that rr is nonnegative and 0≤θ<2π0≤θ<2π (a)(9,0

DochEvi [55]

Answer:

Step-by-step explanation:

Convert rectangle (x , y) to polar coordinates ( r , θ)

$x=r \cos \theta, y= r \sin \theta$

$r=\sqrt{x^2+y^2} , \theta =tan^-^1 (\frac{y}{x} )$

a) converts (9, 0) to polar coordinates ( r , θ)

$r=\sqrt{x^2+y^2} \\\\=\sqrt{9^2+0} \\\\=9$

$\theta= \tan^-^1 (\frac{0}{9} )\\\\=0$

b) Convert $(18,\frac{18}{\sqrt{3} } )$ to polar coordinates ( r, θ)

$r = \sqrt{18^2+(\frac{18}{\sqrt{3} })^2 } \\\\=\sqrt{324+108} \\\\=\sqrt{432}$

$\frac{x}{y} \theta = \tan^-^1(\frac{\frac{18}{\sqrt{3} } }{18} )\\\\= \tan ^-^1(\frac{1}{\sqrt{3} } )\\\\= \frac{\pi}{6}$

c) converts (-5, 5) to polar coordinates ( r , θ)

$r =\sqrt{(-5)^2+(5)^2} \\\\=\sqrt{50} \\\\=5\sqrt{2}$

$\theta=\tan^-^1(\frac{5}{-5} )\\\\= \tan^-^1(-1)\\\\=\frac{3\pi}{4}$

d) converts (-1, √3) to polar coordinates ( r , θ)

$r=\sqrt{(-1)^2+(\sqrt{3})^2 } \\\\= \sqrt{4} \\\\=2$

$\theta=\tan^-^1(\frac{\sqrt{3} }{-1} )\\\=\tan^-^1(-\sqrt{3} )\\\\=\frac{2\pi}{3}$

$= \frac{2\pi}{\sqrt{3} }$

6 0

3 years ago

Solving equations with variables on both sides <br><br><br> 7+9x=6x-2

katrin2010 [14]

Answer:

Here

Step-by-step explanation:

We move all terms to the left:

7+9x-(6x-2)=0

We get rid of parentheses

9x-6x+2+7=0

We add all the numbers together, and all the variables

3x+9=0

We move all terms containing x to the left, all other terms to the right

3x=-9

x=-9/3

x=-3

3 0

3 years ago

Read 2 more answers

What is the value of x in this equation?

andre [41]

The value of x is
-4x + 8 = 42
-4x = 42 -8
-4x = 34
x = -8,5

8 0

3 years ago

If an 11year old child needs to take 1/5 amount of medication per day to heal their head. If a baby has to take 1/5 as much to g

MatroZZZ [7]

Answer:

Step-by-step explanation:

the child takes 1/5.....the baby needs to take 1/5 of what the child takes

so 1/5 of 1/5....." of " in math, means multiply

1/5 * 1/5 = 1/25 of the amount <==

6 0

3 years ago

Use the diagram on the right. How many planes contain both the line and the point

Aloiza [94]

Part (a)

<h3>Answer: 0</h3>

-------------------

Explanation:

Point P is part of 3 planes or faces of this triangular prism:

plane PEF (the front slanted plane)
plane PEH (the left triangular face)
plane PHG (the back rectangular wall)

Notice how each three letter sequence involves "P", though this isn't technically always necessary. I did so to emphasize how point P is involved with these planes.

Each of the three planes mentioned do not involve line FG

Plane PEF only deals with point F
Plane PEH doesn't have any of F or G involved
plane PHG only involves G

So there are no planes that contain line FG and point P.

==================================================

Part (b)

<h3>Answer: 0</h3>

-------------------

Explanation:

It's the same idea as part (a) earlier. The planes involving point G are

plane GQF (triangular face on the right)
plane GFE (bottom rectangular floor)
plane GHP (back rectangular wall)

None of these planes have line EP going through them.

As an alternative, we could reverse things and focus on all of the planes connected to line EP. Those 2 planes are

plane PEH (triangular face on the left)
plane PEF (front slanted rectangular face)

None of these planes have point G located in them.

8 0

3 years ago