What is the derivative of #y = a^9 + (cos(x))^9#? Calculus Basic Differentiation Rules Chain Rule 1 Answer bp Jul 22, 2015 #-9cos^8 x sinx# Explanation: Use power rule to differentiate #cos^9 x# w.r.t cosx and then chain rule to differentiate cos x w.r.t x 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 3169 views around the world You can reuse this answer Creative Commons License