- #36
d_leet
- 1,077
- 1
jkh4 said:okay, i think i start to get it...what you saying is using the equation derive in part a) right?
More or less, yes.
jkh4 said:okay, i think i start to get it...what you saying is using the equation derive in part a) right?
d_leet said:More or less, yes.
jkh4 said:o...
okay so in general, if we want to know the equation for An to do the ratio test, the An equation we need is derive from the f^(n)(x) pattern right?
d_leet said:Yes.
/*Extra Chars*/
jkh4 said:thank you so much
by the way, one side question, can R be negative?
d_leet said:Your welcome, I'm glad to have been of some help. And no R cannot be negative since it is the limit of an absolute value which is never negative.
Wrong for what? Since |x| is non-negative, -|x| is never positive and so -|x|< 1 is true for all x. If you are talking about using the ratio test to find the radius of convergence, you should not have any negative numbers at all. Go back and check your absolute values again. You want |anxn|, not an|xn|!jkh4 said:okay so in that case -|x| < 1 is wrong right?