If cos (A / 2) = 2/5 for angle a / 2 with quadrant 1, then the exact value of cos A is:

Enter numbers to write 0.000328 0.000328 in scientific notation. 1 1 0.000328=3.28 × 0 . 000328 = 3 . 28 × =3.28×10 = 3 . 28 × 10

When solving this problem: 3025/5.5 = a/90.75 you get 49912.5 which would be the length of one of the sides of a square when the area is only 90.75 inches. is that answer correct, why, and how is it possible?

The value of cos 30° is the same as which of the following?