"A circle has a radius of `log_(10) (a^2)`and a circumference of `log_(10)(b^4).`The value of `l
Channel: Doubtnut
Date: 2020-04-12

"A circle has a radius
 of `log_(10) (a^2)`
and a circumference
 of `log_(10)(b^4).`
The value of `log_a b` is equal to 
(a)`1/(4pi)`
 (b) `1/pi`
 (c) `pi`
 (d)
 `2pi`"