How do you find the arc length of the curve f(x)=x^(3/2) over the interval [0,1]?
1 Answer
Sep 6, 2016
Explanation:
The arc length of the curve
s=int_a^bsqrt(1+(f^'(x))^2)dx
Here, we see that
s=int_0^1sqrt(1+(3/2x^(1/2))^2)dx
=int_0^1sqrt(1+9/4x)dx
=int_0^1sqrt((4+9x)/4)dx
=1/2int_0^1sqrt(4+9x)dx
Substitute with
=1/18int_0^1 9sqrt(4+9x)dx
Substitute
=1/18int_4^13sqrtudu
=1/18int_4^13u^(1/2)du
=1/18[u^(3/2)/(3/2)]_4^13
=1/18(2/3)[u^(3/2)]_4^13
=1/27[u^(3/2)]_4^13
=1/27(13^(3/2)-4^(3/2))
=1/27(13^1*13^(1/2)-(2^2)^(3/2))
=1/27(13sqrt13-2^3)
=1/27(13sqrt13-8)