Derivative of Square Root Function using Chain Rule: d/dx(sqrt(5x^2 + 4x + 1))

Published on March 3, 2026

Calculus

Calculate the derivative of y = sqrt(5x^2 + 4x + 1) by applying the Chain Rule, resulting in (5x + 2) / sqrt(5x^2 + 4x + 1).

Question

Answer

The user has presented an image asking for the derivative of the function:
We need to find .
This requires the use of the chain rule.
First, rewrite the square root as a power:
Let . Then .
The chain rule states:
Step 1: Find
Using the power rule for differentiation ( ):
Substituting back :
Step 2: Find
Using the rules for differentiation of sums and powers:
Step 3: Apply the Chain Rule
Step 4: Simplify the result
We can factor out a 2 from the numerator:
Substitute this back:
Cancel the factor of 2:
The derivative is: