Question

Make cos c the subject of
c^2=a^2+b^2-2ab cos c

Answer 1

$We \:have \: \red { c^2=a^2+b^2-2ab cos c}$

$\implies 2abCosC = a^{2} + b^{2} - c^{2}$

$\implies CosC =\frac{ a^{2} + b^{2} - c^{2}}{2ab}$

$\blue { ( Cos C \: is \: subject )}$

Therefore.,

$\red{ CosC}\green{ =\frac{ a^{2} + b^{2} - c^{2}}{2ab}}$

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Answer 2

Answer:

CosC=(a^2+b^2-c^2)/2ab