What is the derivative of sqrt(2x-1)?

1 Answer
Feb 3, 2016

1/(sqrt(2x-1))

Explanation:

This is a case of using the power rule and the chain rule.

First, we note that sqrt(2x-1) can be rewritten as (2x-1)^(1/2).
Now we can apply the power rule, where we multiply the function by the exponent then decrease the exponent by one:
d/dx(2x-1)^(1/2)=(1/2)(2x-1)^(1/2-1)
=1/2(2x-1)^(-1/2)

Then we apply the chain rule, which tells us to multiply this result by the derivative of the "inside" function. In our case, the "inside" function is 2x-1 (because it is inside the square root), and its derivative is simply 2. Our final derivative now becomes:
1/2(2x-1)^(-1/2)*2=(2x-1)^(-1/2)

In radical form, this is 1/(sqrt(2x-1)).