How do you find the derivative of #y=2cosxsinx# Calculus Basic Differentiation Rules Product Rule 1 Answer Alan P. Feb 25, 2015 #2cos(2x)# Explanation: Since #y = 2 cos(x) sin(x)# is the same as #y = sin (2x)# and #(d sin(theta))/(d theta) = cos( theta)# Let #g(a) = sin(a)# and #h(b) = 2b# (So #y = g(h(x))#) By the chain rule: #(d y)/(dx) = (d g(h(x)))/(d h(x)) * (d h(x))/(dx)# #color(white)((dy)(dx))=(d(sin(2x)))/(d(2x)) * (d(2x))/(dx)# #color(white)((dy)(dx))= cos(2x) * 2# or #color(white)((dy)(dx))= 2 cos(2x)# Answer link Related questions What is the Product Rule for derivatives? How do you apply the product rule repeatedly to find the derivative of #f(x) = (x - 3)(2 - 3x)(5 - x)# ? How do you use the product rule to find the derivative of #y=x^2*sin(x)# ? How do you use the product rule to differentiate #y=cos(x)*sin(x)# ? How do you apply the product rule repeatedly to find the derivative of #f(x) = (x^4 +x)*e^x*tan(x)# ? How do you use the product rule to find the derivative of #y=(x^3+2x)*e^x# ? How do you use the product rule to find the derivative of #y=sqrt(x)*cos(x)# ? How do you use the product rule to find the derivative of #y=(1/x^2-3/x^4)*(x+5x^3)# ? How do you use the product rule to find the derivative of #y=sqrt(x)*e^x# ? How do you use the product rule to find the derivative of #y=x*ln(x)# ? See all questions in Product Rule Impact of this question 17952 views around the world You can reuse this answer Creative Commons License