the position vectors of point A and B are (-3,6.3) and (-1,2,4) respectively, relative to an origin. calculate angle AOB

Which approach to the theory-and-research cycle does the following sequence reflect: (1) specific observations suggest generalizations, (2) generalizations produce a tentative theory, (3) the theory is tested through the formation of hypotheses, and (4) hypotheses may provide suggestions for additional observations?

Which value is not a solution of 8x^3 – 1 = 0

Is the square root of 4 plus the square root of 16 rational?