Calculate cos theta to two decimal places. (Use the pic attached inside!!!)

A. 0.61

B. 1.44

C. 0.72

D. 0.43

**i don't get this at all :( pls explain!! Thank youu :)

Question

Calculate cos theta to two decimal places. (Use the pic attached inside!!!)

A.       0.61

B.       1.44

C.       0.72

D.       0.43

**i don't get this at all :( pls explain!! Thank youu :)

anonymous · Answer

attachment

anonymous · Answer

use cosa= b^2+c^2-a^2/2bc then use taylor series

anonymous · Answer

yeah, but i'm confused on the actual steps and such :(

anonymous · Answer

cuz i always get confused with what to plug in where, etc :(

mathstudent55 · Answer

Perfect example for the law of cosines. You have the 3 sides given and are looking for an angle.

anonymous · Answer

okay :) i'm trying to figure out what to plug into where tho in the equation :/

anonymous · Answer

i always forget that exact part :(

mathstudent55 · Answer

|dw:1369708491739:dw|

anonymous · Answer

|dw:1369708527328:dw|