(x^r -1)/(x-1) with r element of Q and x ---> 1?

Question

0

667

1

Guest Dec 11, 2014

+33661

+5

Best Answer

$$\frac{x^r-1}{x-1}=x^{r-1}+x^{r-2}+...+x^{r-r}$$

There are r terms so when x = 1 we have r as the value of the sum, and hence of the limit of (x^r - 1)/(x - 1) as x→1

.

Alan Dec 12, 2014

Alan · Answer 1 · 2014-12-12T09:50:51

$$\frac{x^r-1}{x-1}=x^{r-1}+x^{r-2}+...+x^{r-r}$$

There are r terms so when x = 1 we have r as the value of the sum, and hence of the limit of (x^r - 1)/(x - 1) as x→1

.