given this function(adsbygoogle = window.adsbygoogle || []).push({});

f(x) = x^3+y^3+3x^2-18y^2+81y+5

i should i find the extrema(i hope this is how it is called in english)

so we should have gradf = 0

hence

3x^2+6x = 0 and 3y^2-36y+81 = 0

here i get x = 0 or x = -2 and y = 54/9 or y = 2

now what i want to ask is, which points will i have to take in order to check of extrema?

it will be

P1 = (0,54/9) and P2 = (-2,2)?

P1 = (0,2) and P2 = (-2,54/9)?

which one is the correct?

Thanks in advance

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# Homework Help: Extrema of function

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