Posted by sh on Sunday, December 13, 2009 at 10:33pm.
Find the intervals of increase and decrease for the following function:
y=x√((x1)^4)
y'=[(4x)^(1/2)]+(1/2)((4x)^(1/2))(1)(x)
y'=[(4x)^(1/2)](1/2x)((4x)^(1/2))
y'=((4x)^(1/2))[((4x)^1)1/2x]
I've already factored it, how come the zeros of the derivative aren't 4 and 0?

Calculus  Reiny, Sunday, December 13, 2009 at 10:48pm
If I interpret your first line correctly it is
y = x√((x1)^4)
Isn't that
y = x(x1)^2 ??
then
y' x(2)(x1) + (x1)^2
= (x1)(2x  x + 1)
= (x1)(x+1)
= 0
so x = 1 or x = 1 are the zeros of the derivative.
I don't see where the (4x)'s in your second line come from, there wasn't even a 4x in the equation.

Calculus  sh, Sunday, December 13, 2009 at 10:52pm
Whoops, I combined 2 questions together.
The question is y=x√(4x).

Calculus  Reiny, Sunday, December 13, 2009 at 11:14pm
So what did you get for you factored derivative set equal to zero ?
Mine was (1/2)(4x)^(1/2)(3x8) = 0
x = 8/3
Answer This Question
Related Questions
 Calculus  Find the intervals of increase and decrease for the following ...
 calculus  For the function f(x)=x^3e^x, determine intervals of increase and ...
 calculus help  Produce graphs of f that reveal all the important aspects of the...
 calculus  For the function f(x)= (√1−x) / ( √1+x) find: a. ...
 Calculus  I need help determining the intervals of increase, decrease and the ...
 Calculus  Consider the following function. f(x) = (2 − x)^(e^−x) (a...
 Calculus  Consider the function f (x) = 2x^3  3x^2  72x + 7 Find and classify...
 Calculus  Graph the following function. Find and state the domain, intercepts, ...
 Mathematics  Consider the following function. f(x) = e^(x)/ x^(4) (a) Find the ...
 calculus  Given the function g(x)= (3x) / (2+5x^2 ) find its region of increase...
More Related Questions