If I had the quadratic expression of x^2 + 6x - 4, and wrote it as (x + 3)^2 + 5, what would be the minimum and maximum values of this and why?
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Originally Posted by db5vry If I had the quadratic expression of x^2 + 6x - 4, and wrote it as (x + 3)^2 + 5, what would be the minimum and maximum values of this and why? The minimum value would be 5. This would occur at x = -3 because a squared value cannot be negative so it will be a minimum when (x+3) = 0. The maximum would be infinity
When completing the square of $\displaystyle x^2+6x-4$ I get $\displaystyle (x+3)^2-13$ since $\displaystyle (x+3)^2=x^2+6x+9$, so to get from 9 to -4 you need to minus 13. Just as a heads up.
Originally Posted by db5vry If I had the quadratic expression of x^2 + 6x - 4, and wrote it as (x + 3)^2 + 5 In this case, as Chella pointed out, you have the wrong expression. 9+ 5 is NOT equal to -4. what would be the minimum and maximum values of this and why?
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