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Why should we pay attention to the value of the definition domain when solving the function value domain by discriminant method in senior one mathematics? Please give an example.
For example, f (x) = 4x/x 2- 1. When using the discriminant method, it is wrong to write and explain the domain of X: x ≠ 1 without paying attention. Because when x takes 1, the denominator is 0. Are you still using it? This formula is meaningless. Therefore, it is necessary to determine the definition domain to make the independent variable X meaningful, and then consider the range of the dependent variable Y. (PS I forgot to log in just now ... so post the answer again ... What else can I ask for? I am a senior 3), 3, such as: f (x) = 4x/x 2-655. When using the discriminant method. If you don't pay attention to writing and explaining the domain of x: X ≠ 1 is wrong. Because when x takes 1, the denominator is 0, is it still useful? This formula is meaningless. ,0,y+(2x^2 4x/)/(x^2 2x3)+{2(x^22x)},0,