How do you condense log_3 8 - 4log_3(X^2)?

1 Answer
Apr 18, 2016

X = 8^(1/8)=1.297(cos( (2kpi)/8)+isin((2kpi)/8)), k=0, 1, 2,.,7
The two real solutions are +-1.297, near.y, for k = 0 and k = 4..

Explanation:

Use m log a = log a^m and log( (a^m)^n)=log a^(mn).

log_3 8=log_3((X^2)^4)=log_3X^8
X^8=8
X=8^(1/8)=1.297(cos (2kpi)+isin(2kpi))^(1/8, k=intege (including 0),
Now, X=1.297(cos( (2kpi)/8)+isin((2kpi)/8)), k=0, 1, 2, ...7, for the eight values repeated in a cycle.

The two real solutions are +-1.297, near.y, for k = 0 and k = 4.#