We are executive members who pays $100/year. We also get cash back for every purchase and we pretty much get the membership fee back every year. We are a family of four and we buy most of our home supplies from Costco plus other stuffs. We love Costco but you have to know what you are buying.
Undefined is a term used when a mathematical result has no meaning. More precisely, undefined values occur when an expression is evaluated for input values outside of its domain. ( 1 if no complex numbers) ( 2 if no complex numbers) ( units in radians, no complex infinity)
Thus, the only points at which a function can have a local maximum or minimum are points at which the derivative is zero, as in the left hand graph in figure 5.1.1, or the derivative is undefined, as in the right hand graph. Any value of $x$ for which $f'(x)$ is zero or undefined is called a critical value for $f$.