How do you use the quotient rule to find the derivative of y=x/(3+e^x) ?

1 Answer
Jul 30, 2014

y'=1/(3+e^x)-xe^x/((3+e^x)^2)

Explanation,

Using Quotient Rule,

y=f(x)/g(x), then y'=(f'(x)g(x)−f(x)g'(x))/(g(x))^2

Similarly following for y=x/(3+e^x)

differentiating both side with respect to x,

dy/dx=d/dx(x/(3+e^x))

y'=((3+e^x)(x)'-x(3+e^x)')/((3+e^x)^2

y'=((3+e^x)-x(e^x))/((3+e^x)^2

y'=((3+e^x)-x(e^x))/((3+e^x)^2

y'=1/(3+e^x)-xe^x/((3+e^x)^2)