What's the main reason why people use graphs

Determine the maximum r-value of the polar equation r =3+3 cos 0

Apebble is thrown into a calm lake, ripples are formed from the center and move outward. the water particles in the lake travel in a circular pattern that moves up and down on the surface of a lake, and the energy travels a) diagonally. b) downward. c) horizontally. d) upward.

When the magnetic domains in a material can be aligned, but eventually drift out of alignment, the material is