Question #2de8a

1 Answer
Feb 25, 2015

I am assuming you mean the length of the arc along the given curve between #x=a# and #x=b# (for some arbitrary values #a# and #b#)

In general the arc length of a polynomial #f(x)# is given by:

#int_a^b sqrt(1 + f'(x)^2) dx#

For this specific example:
#f(x) (=y) = ((x^3)/24)+(2/x)#

#rarr f'(x) = x^2/8 - 2/(x^2)#

#f'(x)^2 = x^4/64 - 1/2 + 4/x^2#

#1 + f'(x)^2 = x^4/64 + 1/2 + 4/x^2#

#int_a^b sqrt(1 + f'(x)^2) dx = int_a^b (x^2/8 +2/x^2) dx#

which should be relatively straightforward (once values are established for #a# and #b#).