Can someone please explain how I do the following Maclaurin series? $$f(x) = \ln(3x^2 +4x +1)$$
Asked
Active
Viewed 269 times
-1
-
What have you tried? – Luke Collins Jun 17 '19 at 10:59
2 Answers
0
Note that $$\ln (1+x)=\int \frac {dx}{1+x}=$$
$$\int (1-x+x^2-x^3+...)=x-x^2/2+x^3/3-x^4/4+...$$
Similarly $$ \ln (1+3x)=3x-(3x)^2/2+(3x)^3/3-....$$
Now we get $$ \ln (3x^2+4x+1)=\ln (1+x)+\ln(1+3x)$$
All you have to do is to add the twe series.
Mohammad Riazi-Kermani
- 68,728