Pls, help me. The first answer gets brainliest

Samantha swam upstream for some distance in one hour. she then swam downstream the same river for the same distance in only 12 minutes. if the river flows at 4 mph, how fast can samantha swim in still water?

Sketch one cycle if the cosine function y=2cos2theta

Determine which postulate or theorem can be used to prove that lmn =nmo