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
If you convert 7m to centimetres you get 700
Answer: The required length of the segment AA' is 11 units.
Step-by-step explanation: Given that the point A(5, 11) is reflected across the X-axis.
We are to find the length of the segment AA'.
We know that
if a point (x, y) is reflected across X-axis, then its co-ordinates becomes (x, -y).
So, after reflection, the co-ordinates of the point A(5, 11) becomes A'(5, -11).
Now, we have the following distance formula :
The DISTANCE between two points P(a, b) and Q(c, d) gives the length of the segment PQ as follows :

Therefore, the length of the segment AA' is given by

Thus, the required length of the segment AA' is 11 units.
The way you wrote the question was a bit confusing. Also, there are two variables here. To find the one variable (the number of rolls of wrapping paper) we need to find the number of packages.