In mathematical induction, showing that something works for the first case, or that P1 is true. angle of depression. The angle formed by a horizontal line and an observer's line of sight to an object below. angle of elevation. The angle formed by a horizontal line and an observer's line of sight to an object above.
Plankton's voice is provided by American actor Mr. Lawrence. The voice Lawrence uses for Plankton originated as an imitation of one of his deep-voiced friends from high school. On television, he first used the voice for incidental characters on Rocko's Modern Life.
SpongeBob is voiced by veteran voice actor Tom Kenny. Kenny previously worked with Hillenburg on Rocko's Modern Life, and when Hillenburg created SpongeBob SquarePants, he approached Kenny to voice the character. Hillenburg used Kenny's and other people's personalities to help create the personality of SpongeBob.