hey, i have a couple of questions!

1. A triangle has its vertices at A(-1,3), B(3,6), and C(-4,4). Show that, to three significant figures, cosB(angle A)C = -0.569.

2. The function f is given by f(x) = 2sin(5x-3).

(a) find f"(x)

(b) write down f(x)dx

3. There is a cube, OABCDEFG, wehre the length of each edge is 5 cm. Express the following vectors in terms of i, j, and k.

(a) vector OG

b) vector BD

(c) vector EB

thats all, thanks