please help min and max

[Tueseve728]

y=cos^-1 (x^2)

this is what i have so far...
-2/sq root(1-(x^2)^2

-2x/sq root (1-x^4)

critical point; 0 and 1 this is where i am stuck! I need max value of __ at point (_,_) nad min value __ at point (_,_)

 

[Guest]

can you post the full problem of what you are to solve and do please.

 

[Gene]

Very close except for a typo in the first line of the derivitive.
Critical points are -1,0,1 (which is the domain.)
at x = -1, x^2=1, cos^-1(x^2)=0
Same for x = 1
at x = 0 cos^-1(x^2) = pi/2

 

[Tueseve728]

so the max is pi/2 at point (0,pi/2)
I cant get the min?

Thanks Gene for your help

 

[Gene]

The slope starts with +oo at x=-1, goes thru 0 at x=0 and ends with -oo at x=+1. You can think of the graph as a warped semicircle. The minima are on the x axis at (-1,0) & (1,0). The domain is [-1,1] 'cause the values of cos(u) are in that range.