HELP PLEASE I NEED YOUR HELP

How to choose the sign of the radical in the denominator of the formula for the distance from a point to a line.

The magnitude, m, of an earthquake is defined to be m=log l/s, where i is the intensity of the earthquake (measured by the amplitude of the seismograph wave) and s is the intensity of a “standard” earthquake, which is barely detectable. what is the magnitude of an earthquake that is 1,000 times more intense than a standard earthquake? use a calculator. round your answer to the nearest tenth.

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much