Mathematics for IGCSE & O level - Pythagoras' Theorem And Trigonometry (Section 4 - No. 15)
What is the general formula for the sine rule?
a/sinA = b/sinB = c/sinC
a^2 = b^2 + c^2 - 2bc*cosA
sinA/a = sinB/b = sinC/c
cos A = (b^2 + c^2 - a^2) / 2bc
توضیح
The correct formula is a/sinA = b/sinB = c/sinC.