If #f(x)= cos3x # and #g(x) = sqrt(x+3 #, how do you differentiate #f(g(x)) # using the chain rule? Calculus Basic Differentiation Rules Chain Rule 1 Answer Trevor Ryan. Feb 25, 2016 #(d(f@g)(x))/dx=-3/(2sqrt(x+3))sin(3sqrt(x+3))# Explanation: The composition function #(f@g)(x)# is found as follows : #f[g(x)]=f(sqrt(x+3))# #=cos(3sqrt(x+3))# #therefore(d(f@g)(x))/dx=d/dxcos(3sqrt(x+3))# #=-sin(3sqrt(x+3))*3/2(x+3)^(-1/2)(1)# #=-3/(2sqrt(x+3))sin(3sqrt(x+3))# Answer link Related questions What is the Chain Rule for derivatives? How do you find the derivative of #y= 6cos(x^2)# ? How do you find the derivative of #y=6 cos(x^3+3)# ? How do you find the derivative of #y=e^(x^2)# ? How do you find the derivative of #y=ln(sin(x))# ? How do you find the derivative of #y=ln(e^x+3)# ? How do you find the derivative of #y=tan(5x)# ? How do you find the derivative of #y= (4x-x^2)^10# ? How do you find the derivative of #y= (x^2+3x+5)^(1/4)# ? How do you find the derivative of #y= ((1+x)/(1-x))^3# ? See all questions in Chain Rule Impact of this question 1803 views around the world You can reuse this answer Creative Commons License