Question

http://tinypic.com/r/20freif/5
Calculate cos to two decimal places.
A. -0.14
B. 0.69
C. -0.42
D. -0.07
And how did you get the answer?

Answer 1

D. Law of Cosine

Answer 2

\[C^2 = A^2 + B^2 - 2*A*B *\cos(\theta)\]

where c is always the longest side and a and b are either other sides.