Re: Is x<5 ? (1) x^2 > 5 (2) x^2 + x < 5
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19 May 2023, 01:30
To determine whether x is less than 5, we can evaluate the statements (1) and (2) separately.
Statement (1) x^2 > 5:
This statement indicates that the square of x is greater than 5. If x^2 is greater than 5, it means that x can be either positive or negative. For example, if x is 3, then 3^2 = 9, which is greater than 5. However, if x is -3, then (-3)^2 = 9, which is also greater than 5. Therefore, statement (1) alone does not provide enough information to determine whether x is less than 5.
Statement (2) x^2 + x < 5:
This statement suggests that the sum of x squared and x is less than 5. By rearranging the terms, we have x^2 + x - 5 < 0. This inequality is not easily solvable without further calculations. However, we can determine whether x is less than 5 by analyzing the quadratic equation x^2 + x - 5 = 0. If the roots of this equation are both less than 5, then the statement holds true. Calculating the roots of the equation, we find that they are approximately -2.791 and 1.791. Both of these roots are less than 5. Therefore, we can conclude that x is less than 5 based on statement (2).