Mathematics for IGCSE & O level - Pythagoras' Theorem And Trigonometry (Section 2 - No. 16)
Which of the following formulas correctly represents the Law of Cosines?
a^2 = b^2 + c^2 - 2bc*cosA
a/sinA = b/sinB = c/sinC
c^2 = a^2 + b^2
cosA = b^2+c^2-a^2/2bc
คำอธิบาย
The Law of Cosines is used to find the length of sides or angles of a triangle.