Exercise 19

It can be shown that the derivative formula for the function $f$ defined by $\fe{f}{x}=\frac{2x^3+2x+1}{3+5x^2}$ is $\fe{\fd{f}}{x}=\frac{10x^4+8x^2-10x+6}{25x^4+30x^2+9}$.

Determine the equation of the tangent line to $f$ at $1$.