Answer:
The correct answer option is B. 0.21.
Step-by-step explanation:
We are to find the value of [tex]cos \theta[/tex] using the law of cosines.
We know that the formula of the cosine rule is given by:
[tex] c ^ 2 = a ^ 2 + b ^ 2 - 2 a b cos C [/tex]
So substituting the given values in the above formula:
[tex] 10.9 ^ 2 = 5.8 ^ 2 + 10.5 ^ 2 - 2 (5.8) (10.5) cos C [/tex]
[tex]118.81=33.64+110.25-121.8cosC[/tex]
[tex]118.81 - (33.64+110.25) = -121.8cosC[/tex]
[tex]118.81-143.86=-121.8cosC[/tex]
[tex]cosC=\frac{-25.05}{-121.8}[/tex]
cos C = 0.21
