2 years ago

Make cos C the subject of the formula C?= a? + b? - 2ab cos C

Mathematics

1 answer:

lara31 [8.8K]2 years ago

5 0

<h3>Answer: Choice E</h3>

Work Shown:

$c^2 = a^2 + b^2 - 2ab\cos(C)\\\\c^2 + 2ab\cos(C) = a^2 + b^2\\\\2ab\cos(C) = a^2 + b^2 - c^2\\\\\boldsymbol{\cos(C) = \frac{a^2 + b^2 - c^2}{2ab}}\\\\$

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