Absolute min/max of function. Am I doing something stupid?

[MrDetermination]

Problem: Find abs. min/max of f(x) on specified interval.

x^2+8x+2; -5 < or = x < or = 0



So... dx = 2x+8 = 2(x+4) and -4 is on the interval

Check.



Now. Set f(x) = -5, -4 and 0

f(-5) = -5^2+8(-5)+2 = -25 + (-40) + 2 = -65 +2 = -35



That is what the calculator gets too but the site says -13 instead of -35. And I've done this with about 10 problems.

 

[BigGlenntheHeavy]

\(\displaystyle (-5)^{2} \ = \ 25.\)

 

[Deleted member 4993]

Problem: Find abs. min/max of f(x) on specified interval.

x^2+8x+2; -5 < or = x < or = 0



So... dx = 2x+8 = 2(x+4) and -4 is on the interval

Check.



Now. Set f(x) = -5, -4 and 0

f(-5) = (-5)^2+8(-5)+2 = 25 - 40 + 2 = -13






That is what the calculator gets too but the site says -13 instead of -35. And I've done this with about 10 problems.