1, when △ > 0, the equation has two unequal real roots;

2. When △=0, the equation has two equal real roots;

3. When △

Real numbers include positive numbers, negative numbers and 0. Positive numbers include: positive integers and positive fractions; Negative numbers include: negative integers and negative fractions. Real numbers also include rational numbers and irrational numbers; Rational numbers include integers and fractions. Integers include: positive integer, 0, negative integer. Scores include: positive score and negative score;

The second classification method of fractions: including finite decimal and infinite cyclic decimal; Irrational numbers include positive irrational numbers and negative irrational numbers. Infinitely circulating decimals are called irrational numbers, which are specifically expressed as √2 and √3.

Extended data:

Relevant theorems of real roots;

Theorem 1 (Cartesian sign law)

Polynomial function f (x)? Is the number of positive real roots equal to f (x)? The number of sign changes of non-zero coefficients, or equal to an even number smaller than the number of changes; f ( x)？ Is the number of negative real roots equal to f (-x)? The sign variation of non-zero coefficient, or equal to an even number less than the variation.

Theorem 2

Count c? Is it f (x)? Necessary and sufficient conditions for the root of f (x)? Is divisible by x-C.

Theorem 3

Every polynomial with real coefficients whose degree is greater than 0 can be decomposed into the product of the first and second irreducible factors of real coefficients.