Question

Find the sum of the x-coordinates of the intersection of x^2 + y^2 = 36 and x^2 - y^2 = 6.

Answer 1

The given equations are,
x²+y²=36 -----------(1)
x²-y²=6 --------------(2)
For the intersection of these curves Adding (1) and (2) we get,
2x²=42
or, x=⁺₋√21
∴, The sum of the x-coordinates is:
√21+(-√21)=0