Find the derivative of y=5^(1-4x)

lny=(1-4x)ln5

Can I split it?
lny=ln5-4xln5
1/y dy/dx = -[4ln5/(4xln5)^2]
dy/dx=-[4ln5/(4xln5)^2]y

Thanks.

Can I split it?

lny=ln5-4xln5

Yes, that is valid.

ln y = ln 5 - (4 ln 5) x

since [4 ln 5 is a constant]

(1/y) dy/dx = 0 - (4 ln 5) dx/dx

Thank you!

You're welcome! Yes, you can split the equation.

Starting from the equation lny = ln5 - 4xln5, we want to find the derivative of y with respect to x (dy/dx).

We can use the property of logarithms, which states that ln(a/b) = ln(a) - ln(b), to rewrite ln5 - 4xln5 as ln(5/(5^4x)).

So now the equation becomes lny = ln(5/(5^4x)).

Next, we differentiate both sides of the equation implicitly with respect to x.

On the left side, we use the chain rule:

d/dx(lny) = (1/y) * (dy/dx).

On the right side, we differentiate ln(5/(5^4x)) term by term.

The derivative of ln(5) is 0 because it's a constant with respect to x.

For the derivative of ln(5^4x), we use the chain rule again.

The derivative of ln(u), where u is a function of x, is (1/u) * du/dx. In this case, u = 5^4x.

So, the derivative of ln(5^4x) with respect to x is (1/5^4x) * (d/dx(5^4x)).

Using the chain rule, we have (1/5^4x) * (5^4 * d/dx(x)).

Simplifying further, we get (1/5^4x) * (5^4 * 1).

Therefore, the derivative of ln(5^4x) is 1.

Substituting these values back into our equation, we have:

(1/y) * (dy/dx) = 0 - (1/5^4x).

Multiplying both sides by y, we get:

dy/dx = -(1/5^4x) * y.

Since y = 5^(1-4x), we can substitute its value into the equation:

dy/dx = -(1/5^4x) * 5^(1-4x).

Simplifying further, we have:

dy/dx = -(1/5^4x) * 5^(1) * 5^(-4x).

And finally:

dy/dx = -[4ln5/(4xln5)^2]y.

I hope this explanation helps! Let me know if you have any further questions.