\
Step 1 :
\Arc length :
\The length of a curve with polar equation is
.
Step 2 :
\The polar equation is .
Apply derivative on each side with respect to .
The exact length of the polar curve is .
Substitute and
in above equation.
Consider .
When .
When .
.
Substitute corresponding values in L.
\The exact length of curve is
Solution :
\The exact length of curve is
\