Find three nonzero terms of the Maclaurin series of the function

$f(x)={3/5} tan5x/x$

Using the maclaurin series i found them to be..

$3/5+x^2/25+2x^4/25$

Is this correct? If not what is the answer so I can find out where i went wrong. Im pretty sure its wrong

Thanks for any help

Consider $$\tan(y)=y+\frac{y^3}{3}+\frac{2 y^5}{15}+O\left(y^7\right)$$ Replace $y$ by $5x$.
• Ive returned two separate answers, which is correct? $3+25x^2+250x^4$ and $5+125/3*x^2+1250/5*x^4$ – someguy May 7 '16 at 9:02
• You cannot get two different results. Write your rexpression using the result for $\tan(5x)$ from $\tan(y)$ with $y=5x$ and adjust the coefficients. One of your two answers is correct. Now, your turn ! – Claude Leibovici May 7 '16 at 9:17