# Trig

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Can you show us how to use law of cosines to show that theta equals inverse cosine of (a^2 + b^2 -484)/(2ab) where a^2=(7+xcos a)^2 + (28-xsin a)^2 and b^2=(7+xcos a)^2 + (xsin a -6)^2? Thanks

• Trig -

Lisa, saw that one last night,
in xcosa and xsina.
secondly where does x come in ?

I have a triangle with sides a and b and Ø as its contained angle.

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