Identify outer function: Identify the outer function and its derivative.The outer function is the cosine function, and the derivative of cos(u) with respect to u is −sin(u).
Identify inner function: Identify the inner function and its derivative.The inner function is ln(6x), and the derivative of ln(u) with respect to u is 1/u. Therefore, the derivative of ln(6x) with respect to x is 1/(6x) multiplied by the derivative of 6x with respect to x, which is 6.
Apply chain rule: Apply the chain rule.The chain rule states that the derivative of a composite function f(g(x)) is f′(g(x))⋅g′(x). Here, f(u)=cos(u) and g(x)=ln(6x), so we need to multiply the derivative of the outer function by the derivative of the inner function.
Perform multiplication: Perform the multiplication to find the derivative.f′(x)=−sin(ln(6x))⋅(6x1⋅6)
Simplify expression: Simplify the expression.f′(x)=−sin(ln(6x))⋅(6x6)f′(x)=−sin(ln(6x))⋅(x1)
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