How do extraneous solutions arise?
1 Answer
In general, extraneous solutions arise when we perform non-invertible operations on both sides of an equation. (That is, they sometimes arise, but not always.)
Non-invertible operations include: raising to an even power (odd powers are invertible), multiplying by zero, and combining sums and differences of logarithms.
Example :
The equations:
Square both sides of
Square both sides of