Question and Answers Forum

All Questions      Topic List

Algebra Questions

Previous in All Question      Next in All Question      

Previous in Algebra      Next in Algebra      

Question Number 9324 by uchechukwu okorie favour last updated on 30/Nov/16

if  x=((a(1−r^n ))/(1−r)) make r the   subject of the formula

$${if}\:\:{x}=\frac{{a}\left(\mathrm{1}−{r}^{{n}} \right)}{\mathrm{1}−{r}}\:{make}\:{r}\:{the}\: \\ $$$${subject}\:{of}\:{the}\:{formula} \\ $$

Answered by mrW last updated on 30/Nov/16

let k=(x/a)  k=((1−r^n )/(1−r))  k−kr=1−r^n   r^n −kr+(k−1)=0  I don′t think it is possible to get  a formula for r in terms of n and k.

$$\mathrm{let}\:\mathrm{k}=\frac{\mathrm{x}}{\mathrm{a}} \\ $$$$\mathrm{k}=\frac{\mathrm{1}−\mathrm{r}^{\mathrm{n}} }{\mathrm{1}−\mathrm{r}} \\ $$$$\mathrm{k}−\mathrm{kr}=\mathrm{1}−\mathrm{r}^{\mathrm{n}} \\ $$$$\mathrm{r}^{\mathrm{n}} −\mathrm{kr}+\left(\mathrm{k}−\mathrm{1}\right)=\mathrm{0} \\ $$$$\mathrm{I}\:\mathrm{don}'\mathrm{t}\:\mathrm{think}\:\mathrm{it}\:\mathrm{is}\:\mathrm{possible}\:\mathrm{to}\:\mathrm{get} \\ $$$$\mathrm{a}\:\mathrm{formula}\:\mathrm{for}\:\mathrm{r}\:\mathrm{in}\:\mathrm{terms}\:\mathrm{of}\:\mathrm{n}\:\mathrm{and}\:\mathrm{k}. \\ $$

Commented by uchechukwu okorie favour last updated on 30/Nov/16

hmmm

$${hmmm} \\ $$

Terms of Service

Privacy Policy

Contact: info@tinkutara.com