Therefore, the truth that 0 can't be the denominator and divisor in elementary and secondary mathematics is still valid in higher mathematics.
Therefore, just because it is advanced mathematics, we can't abandon these rules in primary and secondary mathematics.
Higher mathematics has expanded the scope of "number", so some formulas that primary and secondary mathematics can't do, meaningless formulas, have become meaningful in higher mathematics.
Usually, even after expanding from real number set to complex number set, negative numbers can open square roots.
However, no matter how to expand the scope of "number", everyone can't regard ∞ as a definite number, let alone define "arbitrary number" as a definite number. Therefore, 0 cannot be used as denominator or divisor, which is still unsolved in higher mathematics.