+0  
 
+1
185
1
avatar

What is the min of x^3-3x for x > 0?

Guest Mar 21, 2017
 #1
avatar+87334 
+2

Take the derivative and set this to 0......and we have

 

3x^2 - 3   = 0

 

3(x^2 - 1) = 0    divide by 3

 

x^2 - 1   = 0        factor

 

(x + 1) (  x - 1)  = 0    setting each factor to 0 and we have that

 

x = - 1     and  x = 1    so  these are the critical points

 

Taking the second derivative, we have

 

6x   .......   and putting x = 1   into this  we get   6(1)  = 6

 

This indicates a minimum when x = 1   and y = (1)^3 - 3(1)   =  -2

 

So....the minimum point is -2 when x > 0

 

 

cool cool cool

CPhill  Mar 21, 2017

9 Online Users

avatar
avatar

New Privacy Policy

We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive information about your use of our website.
For more information: our cookie policy and privacy policy.