[administration]

Q. What is the minimum value of (x^2+6x+7) / (x^2+6x+16) ?

asked by Divya Malhotra

[Wonder Boy]

(x^2+6x+7)/(x^2+6x+16)
= (x^2+6x+16 – 9)/(x^2+6x+16)
= 1 – {9/(x^2+6x+16)}
= 1 – {9/((x + 3)^2 + 7)}

This exp will be minimum when {9/((x + 3)^2 + 7)} is maximum
=> ((x + 3)^2 + 7) is minimum, which at x = -3 and value is 7

=> So, minimum value is 1 – 9/7 = -2/7

 

ans by Hemant Yadav

[Author]

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