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zepelin [54]
3 years ago
8

Rewrite in polar form: x^2+y^2-2y=7

Mathematics
2 answers:
Alchen [17]3 years ago
8 0
X²+y²-2y=7
using the formula that links Cartesian to Polar coordinates
x=rcosθ and y=r sin θ
substituting into our expression we get:
(r cos θ)²+(r sin θ)²-2rsinθ=7
expanding the brackets we obtain:
r²cos²θ+r²sin²θ=7+2rsinθ
r²(cos²θ+sin²θ)=7+2rsinθ
using trigonometric identity:
cos²θ+sin²θ=1
thus
r²=2rsinθ+7
Answer: r²=2rsinθ+7
Valentin [98]3 years ago
6 0

Answer: I just took the test and got 100%

1. D, (x-3)^2 + y^2 = 9

2. A, x^2 + y^2 = 25

3. C, r = 12 sec θ

4. D, r^2 = 2r sin θ + 7

Feel free to mark as Brainliest :)

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The hypotenuse of a right triangle is 15cm, and the shorter leg is 9cm. Find the length of the other leg
pishuonlain [190]

Hello!

If you add up the squares of the two legs, it will equal the square of the hypotenuse. As we already have the hypotenuse, we will subtract.

225-81=144

Now we find the square root.

√144=12

Therefore, the other leg is 12 cm long.

I hope this helps!

3 0
2 years ago
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Use the fundamental identities and appropriate algebraic operations to simplify the following expression. (18 +tan x) (18-tan x)
andrezito [222]

Answer:

a) \left(18+\tan \left(x\right)\right)\left(18-\tan \left(x\right)\right)+\sec ^2\left(x\right)=325

b) The lowest point of y=\cos \left(x\right), 0\leq x\leq 2\pi is when x = \pi

Step-by-step explanation:

a) To simplify the expression \left(18+\tan \left(x\right)\right)\left(18-\tan \left(x\right)\right)+\sec ^2\left(x\right) you must:

Apply Difference of Two Squares Formula: \left(a+b\right)\left(a-b\right)=a^2-b^2

a=18,\:b=\tan \left(x\right)

\left(18+\tan \left(x\right)\right)\left(18-\tan \left(x\right)\right)=18^2-\tan ^2\left(x\right)=324-\tan ^2\left(x\right)

324-\tan ^2\left(x\right)+\sec ^2\left(x\right)

Apply the Pythagorean Identity 1+\tan ^2\left(x\right)=\sec ^2\left(x\right)

From the Pythagorean Identity, we know that 1=-\tan ^2\left(x\right)+\sec ^2\left(x\right)

Therefore,

324[-\tan ^2\left(x\right)+\sec ^2\left(x\right))]\\324[+1]\\325

b) According with the below graph, the lowest point of y=\cos \left(x\right), 0\leq x\leq 2\pi is when x = \pi

3 0
3 years ago
Beth has 4900 feet of fencing available to enclose a rectangular field. one side of the field lies along a river, so only three
Illusion [34]

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Area (A) = L · x

A  = (\frac{4900 - x}{2}) (x)

    = \frac{4900x - x^2}{2}

4 0
3 years ago
Find the total surface area.
Ede4ka [16]

Hey love! <3

Answer:

The right answer is A = 49.6 π ft^2

Step-by-step explanation:

<em><u>(Let pi = 3.1415926535898)</u></em>

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<em>So if r = 4 ft</em>

<em>and h = 2.2 ft</em>

<em>A= 2π(4)(2.2)+2π(4)^2</em>

<em>Once we've plugged in our formulas our final surface area is A =</em><em> 49.6 π ft2</em>

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<em />

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oksian1 [2.3K]
Yes yes it isssssssssss
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