Question

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

Answer 1

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

Answer 2

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 :)