Use the 1/2 power: $\displaystyle \left(\frac{(-3i)(3i)}{(2+ i)(2- i)}\right)^{1/2}$
What was wrong with doing exactly what you were told to do?
What I know: common logarithms use base-10.
What I think I know: a logarithm is an exponent.
I don't know how to parlay my limited knowledge into a solution, please help
"Choose two numbers". Okay, I choose 3 an 7. "Take their common logarithms" log(3)= 0.4771 and log(7)= 0.8451. "Add the logarithms" log(3)+ log(7)= 0.4771+ 0.8451= 1.3222. "Take the logarithm of their product". 3*7= 21 and log(21)= 1.3222. Hmmm! Now choose three numbers and try it again!
In the future post two different questions in different threads. People who have already responded to the first question might not look at the thread again and not see the new question.