Use the law of cosines to find the value of cos theta. Round your answer to two decimal places.

Question

anonymous · Answer

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unklerhaukus · Answer

Do you know the law of cosines?

anonymous · Answer

no idea i just left it alone and moved on thanks anyways

unklerhaukus · Answer

For any triangle with angles A,B,C, 
and with opposite sides (to these angles) respectively a,b,c 

$$c^2=a^2+b^2-2ab\cos C$$

unklerhaukus · Answer

so if you look are your picture

Which side do you think is side c ?

unklerhaukus · Answer

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the side c, is the side opposite to the angle theta (angle C)

so

$$(5.7)^2 = (9.8)^2+(10.2^)2-2(9.8)(10.2)\cos(\theta)$$

unklerhaukus · Answer

*$$(5.7)^2 = (9.8)^2+(10.2)^2-2(9.8)(10.2)\cos(\theta)$$