How and why land and sea breezes form?

Let f(x) = x4- 8x2 . find the relativeextrema of this function using the second derivative test.

Arunner is training for an upcoming marathon by running around a 100-m-diameter circular track at constant speed. let a coordinate system have its origin at the center of the circle with the x-axis pointing east and the y-axis north. the runner starts at (x, y) = (50 m, 0 m) and runs 2.5 times around the track in a clockwise direction.

Apatient has a history of poor nutrition. he has skin rashes, bleeding gums, and a cut that hasn’t healed in a long time. what vitamin deficiency most likely caused this symptom?