The answer is 11 degrees if you want to know why this is the answer reply to my comment
Answer:
3.1415967382
Step-by-step explanation:
The angle between two vectors is:
CosФ = u - v / Magnitude(u) x magnitude(v)
Magnitude of u = SQRT(7^2 + -2^2) = SQRT(49 +4) = SQRT(53)
Magnitude of v = SQRT(-1^2 +2^2) = SQRT(1 +4) = SQRT(5)
u x v = (7 x -1) + (-2 x 2) = -7 + -4 = -11
cosФ = -11 / sqrt(53) x sqrt(5)
cosФ = -11sqrt265) / 265
Ф =cos^-1(-11sqrt265) / 265)
Ф=132.51 degrees.
8
A. Delivery is $20. One cord is $120.
B. 1 1/2 cord costs $200. ($180 for the cord and $20 for the delivery)
(I can’t see the full problem for 9)