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Question

Question: How do you find the derivative of \( {4^{6x}} \) ?...

How do you find the derivative of 46x{4^{6x}} ?

Explanation

Solution

In solving the question, first assume the given expression to a variable yy , i.e., y=46xy = {4^{6x}} .Perform differentiation, This will give us dydx=ddx46x\dfrac{{dy}}{{dx}} = \dfrac{d}{{dx}}{4^{6x}} , now differentiate this equation by using identity ddxax=axloga\dfrac{d}{{dx}}{a^x} = {a^x}\log a and chain rule on the RHS, then we will get the required result.

Complete step-by-step solution:
Given expression is 46x{4^{6x}} ,
Now assume the given expression as variable yy , we will get,
y=46xy = {4^{6x}} ,
Now deriving on both sides we get,
ddxy=ddx46x\dfrac{d}{{dx}}y = \dfrac{d}{{dx}}{4^{6x}} ,
Differentiate using the chain rule, which states that ddx(f(g(x)))=f(g(x))g(x)\dfrac{d}{{dx}}\left( {f\left( {g\left( x \right)} \right)} \right) = f'\left( {g\left( x \right)} \right)g'\left( x \right) where f(x)=4xf\left( x \right) = {4^x} and g(x)=6xg\left( x \right) = 6x .
Using chain rule, let u=6xu = 6x ,
ddx4uddx6x\Rightarrow \dfrac{d}{{dx}}{4^u}\dfrac{d}{{dx}}6x ,
Now differentiating using exponential Rule which states that ddxau=auloga\dfrac{d}{{dx}}{a^u} = {a^u}\log a where a=4a = 4 , we get,
4ulog4ddx6x\Rightarrow {4^u}\log 4\dfrac{d}{{dx}}6x ,
Now substituting the value of u we get,
46xlog4ddx6x\Rightarrow {4^{6x}}\log 4\dfrac{d}{{dx}}6x ,
Since 66 is constant with respect to xx , the derivative of 6x6x with respect to xx is 6ddxx6\dfrac{d}{{dx}}x .
Now expression becomes,
46xlog4(6ddxx)\Rightarrow {4^{6x}}\log 4\left( {6\dfrac{d}{{dx}}x} \right) ,
Now simplifying we get,
6(46xlog4(ddxx))\Rightarrow 6\left( {{4^{6x}}\log 4\left( {\dfrac{d}{{dx}}x} \right)} \right) ,
Now we know that derivative of xx with respect to xx is 1, the expression becomes,
646xlog4\Rightarrow 6 \cdot {4^{6x}}\log 4 ,
So the derivative of the given expression 46x{4^{6x}} is 6log446x6 \cdot \log 4 \cdot {4^{6x}} .

\therefore The differentiation value of 46x{4^{6x}} is 6log446x6 \cdot \log 4 \cdot {4^{6x}} .

Note: Differentiation is the method of evaluating a function’s derivative at any time. Some of the fundamental rules for differentiation are given below, and using these rules we can solve differentiation questions easily.
Sum or difference rule: When the function is the sum or difference of two functions, the derivative is the sum or difference of derivative of each function, i.e.,
If f(x)=u(x)±v(x)f\left( x \right) = u\left( x \right) \pm v\left( x \right) ,
Then f(x)=u(x)±v(x)f'\left( x \right) = u'\left( x \right) \pm v'\left( x \right) .
Product rule: When the function is the product of two functions, the derivative is the sum or difference of derivative of each function, i.e.,
If f(x)=u(x)×v(x)f\left( x \right) = u\left( x \right) \times v\left( x \right) ,
then f(x)=u(x)v(x)+u(x)v(x)f'\left( x \right) = u'\left( x \right)v\left( x \right) + u\left( x \right)v'\left( x \right)
Quotient Rule: If the function is in the form of two functions u(x)v(x)\dfrac{{u\left( x \right)}}{{v\left( x \right)}} , the derivative of the function can be expressed as,
f(x)=u(x)v(x)u(x)v(x)(v(x))2f'\left( x \right) = \dfrac{{u'\left( x \right)v\left( x \right) - u\left( x \right)v'\left( x \right)}}{{{{\left( {v\left( x \right)} \right)}^2}}} .
Chain Rule:
If y=f(x)=g(u)y = f\left( x \right) = g\left( u \right) ,
And if u=h(x)u = h\left( x \right) ,
Then dydx=dydu×dudx\dfrac{{dy}}{{dx}} = \dfrac{{dy}}{{du}} \times \dfrac{{du}}{{dx}} .