log9243 = log3243/log39
= 5/2
Think of it like this. Since 9 = 3^2, 9^n = (3^2)^n = 3^2n
That is, the power of 3 will be twice the power of 9.
Logs work the same way. The power of 9 needed to get to n is half the power of 3. Since log9n is the power of 9 needed to produce n, it will be half the power of 3 needed.
Evaluate the expression below
log 243
9
1 answer
3 answers