Here's the algebraic solution without using polar coordinates.....
( x + 6)^2 + ( y - 9)^2 = 52
x^2 + y^2 = 13 → y^2 = 13 - x^2 → y = ± √(13 - x^2)
Let us first guess that y = the positive root of √(13 - x^2)
Substitute this into the first equation.........
(x + 6)^2 + ( √(13 - x^2) - 9)^2 = 52 expand
x^2 + 12x + 36 + 13 - x^2 - 18 √(13 - x^2) + 81 = 52 simplify
12x - 18 √(13 - x^2) = -78 divide through by 6
2x - 3 √(13 - x^2) = -13 rearrange
2x + 13 = 3√(13 - x^2) square both sides
4x^2 + 52x + 169 = 9(13 - x^2) simplify
4x^2 + 52x +169 = 117 - 9x^2 rearrange
13x^2 + 52x + 52 = 0 divide through by 13
x^2 + 4x + 4 = 0 factor
(x + 2)^2 = 0 take the square root of both sides
x + 2 = 0 so x = -2 and y = √(13 - x^2) = √(13 - (-2)^2) = √(13 - 4) = √9 = 3
And we have seen above that (-2, 3) is a solution
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Now...let us assume that the negative root of √(13 - x^2) also might work for y
The algebra looks eerily similar to what we did before...........
(x + 6)^2 + ( -√(13 - x^2) - 9)^2 = 52
x ^2 + 12x + 36 + 13 - x^2 + 18√(13 - x^2) + 81 = 52
12x + 18√(13 - x^2) = -78
2x + 3√(13 - x^2) = -13
2x + 13 = -3√(13 - x^2)
4x^2 + 52x + 169 = 9(13 - x^2)
4x^2 + 52x + 169 = 117 - 9x^2
13x^2 + 52x + 52 = 0
x^2 + 4x + 4 = 0
(x + 2)^2 = 0
x + 2 = 0 ... so.... x = -2 and y = -√(13 - x^2) =- √(13 - (-2)^2) =- √(13 - 4) = -√9 = -3
However...notice the problem in the first equation if y = -3
(-2 + 6)^2 + (-3 - 9)^2 = 4^2 + (-12)^2 = 16 + 144 = 160 and this does not equal 52 !!!
So....we only have one solution.....
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See???......I told you it was messy !!!
Let us offer up our many sacrifices to the Altar of Desmos, The Spirit of the Graphing Calculator
( x + 6)^2 + ( y - 9)^2 = 52
x^2 + y^2 = 13
The Algebra for this one could get a little messy......I might use a graphical approach....
https://www.desmos.com/calculator/cnkpzxaqrm
These are two circles that are tangent to each other....
The only "solution" point occurs at (-2, 3)....... And this is the point of tangency.......
Here's the algebraic solution without using polar coordinates.....
( x + 6)^2 + ( y - 9)^2 = 52
x^2 + y^2 = 13 → y^2 = 13 - x^2 → y = ± √(13 - x^2)
Let us first guess that y = the positive root of √(13 - x^2)
Substitute this into the first equation.........
(x + 6)^2 + ( √(13 - x^2) - 9)^2 = 52 expand
x^2 + 12x + 36 + 13 - x^2 - 18 √(13 - x^2) + 81 = 52 simplify
12x - 18 √(13 - x^2) = -78 divide through by 6
2x - 3 √(13 - x^2) = -13 rearrange
2x + 13 = 3√(13 - x^2) square both sides
4x^2 + 52x + 169 = 9(13 - x^2) simplify
4x^2 + 52x +169 = 117 - 9x^2 rearrange
13x^2 + 52x + 52 = 0 divide through by 13
x^2 + 4x + 4 = 0 factor
(x + 2)^2 = 0 take the square root of both sides
x + 2 = 0 so x = -2 and y = √(13 - x^2) = √(13 - (-2)^2) = √(13 - 4) = √9 = 3
And we have seen above that (-2, 3) is a solution
----------------------------------------------------------------------------------------------------
Now...let us assume that the negative root of √(13 - x^2) also might work for y
The algebra looks eerily similar to what we did before...........
(x + 6)^2 + ( -√(13 - x^2) - 9)^2 = 52
x ^2 + 12x + 36 + 13 - x^2 + 18√(13 - x^2) + 81 = 52
12x + 18√(13 - x^2) = -78
2x + 3√(13 - x^2) = -13
2x + 13 = -3√(13 - x^2)
4x^2 + 52x + 169 = 9(13 - x^2)
4x^2 + 52x + 169 = 117 - 9x^2
13x^2 + 52x + 52 = 0
x^2 + 4x + 4 = 0
(x + 2)^2 = 0
x + 2 = 0 ... so.... x = -2 and y = -√(13 - x^2) =- √(13 - (-2)^2) =- √(13 - 4) = -√9 = -3
However...notice the problem in the first equation if y = -3
(-2 + 6)^2 + (-3 - 9)^2 = 4^2 + (-12)^2 = 16 + 144 = 160 and this does not equal 52 !!!
So....we only have one solution.....
--------------------------------------------------------------------------------------------------
See???......I told you it was messy !!!
Let us offer up our many sacrifices to the Altar of Desmos, The Spirit of the Graphing Calculator