Which of these is the Law of Cosines?
c2=a2+b2−2abcosCc^2 = a^2 + b^2 - 2ab\\cos Cc2=a2+b2−2abcosC
sin2A+cos2A=1\\sin^2 A + \\cos^2 A = 1sin2A+cos2A=1
a/sinA=b/sinBa/\\sin A = b/\\sin Ba/sinA=b/sinB
tanA=sinA/cosA\\tan A = \\sin A / \\cos AtanA=sinA/cosA