Question

How do you get the relative maximum and minimum values of a x3 graph that does not have definite curves? For instance, in the graph of x^3-6x^2=15 , the graph looks like a traditional x^3 graph

Answer 1

first derivative = 0

Answer 2

Is it even possible to have a relative maximum or minimum for this type of graph? When you plug it into the clculator you can see that the curves are connected, which takes away the possibility of getting an accurate point

Answer 3

if y=x^3-6x^2-15
y'=3x^2-12x
which will gives you 2 critical points:
x=0 & x=4
I think (without checking) x=0 is local max
check x=4

Answer 4

x=4 should be local min

Answer 5

here is the graph - you can see that x=0 is local max & x=4 is loc min

Answer 6

sorry I had typo, it's + 15

Answer 7

This is what the graph looks like

Answer 8

how do you find it with that?

Answer 9

this one :
y=x^3 - 6x^2 +15
see attached - still has local max @ x=0 & local min @ x=4

Answer 10

I took first derivative:
y=3x^2 -12x
critical points when y'=0
solve it for x

Answer 11

Go to http://www.wolframalpha.com and then type
extrema of x^3-6x^2

Answer 12

that one looks like y=x^3
y'=3x^2
y'=0 when x=0
it's not min or max, it's called "Inflection point"
see: http://en.wikipedia.org/wiki/Inflection_point

Answer 13

good?

Answer 14

awesome