Billy J.

asked • 04/02/16

Confused on law of cosines with the given SAS values

I have 
a = 65
b = ?
c = 50
 
<A = ?
<B = ?
<C = 52
 
Now I understand the b2 = a2 + c2 - 2ac*CosB and the other 2 variants of the formula but how do I solve it when I don't have a value to put for Cos B in the formula above?

2 Answers By Expert Tutors

By:

Jim L. answered • 04/02/16

Personable, effective English, Math and Science Tutor

Billy J.

Thank you for some reason my brain completely skipped on that
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04/02/16

Billy J.

So I did that and I ended up with sin-1(1.0244) which is a domain error does that mean the answer is it is not a valid triangle?
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04/02/16

Mark M. answered • 04/02/16

Mathematics Teacher - NCLB Highly Qualified

Billy J.

So I did that and I ended up with sin-1(1.0244) which is a domain error does that mean the answer is it is not a valid triangle?
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04/02/16

Billy J.

sin-1(1.0244)** is what I meant 
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04/02/16

Mark M.

tutor
sin 52° / 50 = sin A / 65
0.7880 / 50 ≈ sin A / 65
51.22 / 50 ≈ sin A
1.02 ≈ sin A
Either not a valid triangle, or the information is inaccurate.
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04/02/16

Billy J.

Thank you for the help
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04/02/16

Mark M.

tutor
You are welcome!
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04/02/16

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