What is the difference between -2^4 and (-2)^4

I know the answer but how do you explain it?

Which of the following equations is of the parabola whose vertex is at (2, 3), axis of symmetry parallel to the y-axis and p = 4? a.)y-3 = 1/16 (x-2)^2 b.)y+3 = -1/16 (x+2)^2 c.)x-2 = 1/16 (y-3)^2

Find the ratios of the corresponding sides

Cos^2x+cos^2(120°+x)+cos^2(120°-x)i need this asap. pls me