How to find the derivative of #3arccos(x/2)#? Calculus Differentiating Trigonometric Functions Differentiating Inverse Trigonometric Functions 1 Answer bp Apr 16, 2015 -#3/[2sqrt(1-x^2/4)]# Let y= 3 arc cos#x/2#, so that #y/3# = arc cos#x/2# Thus, cos#y/3#= #x/2# and hence sin#y/3# = #sqrt(1- x^2/4)# Now differentiate, -#1/3# sin#y/3# #dy/dx# = #1/2# #dy/dx#= -#3/[2sin(y/3)]# = -#3/[2sqrt(1-x^2/4)]# Answer link Related questions What is the derivative of #f(x)=sin^-1(x)# ? What is the derivative of #f(x)=cos^-1(x)# ? What is the derivative of #f(x)=tan^-1(x)# ? What is the derivative of #f(x)=sec^-1(x)# ? What is the derivative of #f(x)=csc^-1(x)# ? What is the derivative of #f(x)=cot^-1(x)# ? What is the derivative of #f(x)=(cos^-1(x))/x# ? What is the derivative of #f(x)=tan^-1(e^x)# ? What is the derivative of #f(x)=cos^-1(x^3)# ? What is the derivative of #f(x)=ln(sin^-1(x))# ? See all questions in Differentiating Inverse Trigonometric Functions Impact of this question 2295 views around the world You can reuse this answer Creative Commons License