# Math Help - Calculus

1. ## Calculus

How does one find the length of y = x^3/3 + 1/(4x) from x = 1 to 2?

2. Originally Posted by Unenlightened
How does one find the length of y = x^3/3 + 1/(4x) from x = 1 to 2?
The formula for arc length is $s= \int_{a}^{b}\sqrt{a+f'[x]^2}dx$, where the arc runs from a to b. Look familiar?

3. Originally Posted by Unenlightened
How does one find the length of y = x^3/3 + 1/(4x) from x = 1 to 2?
arclenght is given by $\int_a^{b}\sqrt{1+f'(x)^2}dx$

so in this case it would be $\int_1^{2}\sqrt{1+\bigg(x^2+\frac{-1}{(4x)^2}\bigg)^2}dx$

4. Cheers - it's not actually for me. A friend was asking me and I couldn't remember how to do it. We don't use numbers anymore in my course