How do you find the derivative of f(x) = x + sqrt(x)?

2 Answers
May 18, 2017

1+sqrt(x)/(2x)

Explanation:

Chain Rule is not needed here. Just use thee Power Rule.

f(x)=x+sqrt(x)
f(x)=x+(x)^(1/2)
f'(x)=1+1/2x^(1/2-1)
f'(x)=1+1/2(1/sqrt(x))=1+sqrt(x)/(2x)

May 18, 2017

Use algebra and the power rule.

f'(x) = 1 + 1/2x^(-1/2)

Explanation:

When f(x) = x^n, the power rule states that the derivative follows the trend f'(x) = nx^(n-1).

Applied to your specific problem...

f(x) = x + sqrt(x)

(Use your knowledge of algebra to rewrite the root as an exponent...)

f(x) = x + x^(1/2)

(Now just take the derivative by using the power rule...)

f'(x) = 1 + 1/2x^(-1/2)