If (cos(A) - sin(A))/(cos(A) + sin(A)) = (1 - sqrt(3))/(1 + sqrt(3)) and 0 < A < 90, then find A.
+128407 cos A - sin A 1 - sqrt (3)
____________ = ____________ cross - multiply
cos A + sin A 1 + sqrt (3)
(cos A - sin A) ( 1 + sqrt (3)) = (cos A + sinA) ( 1 - sqrt (3) )
cosA + sqrt (3)cos A - sin A - sqrt (3)sin A = cos A - sqrt(3)cos A + sin A - sqrt (3) sin A
Simplify as
2sqrt(3) cos A = 2sin A
sqrt (3) cos A = sin A
sqrt (3) = sin A / cos A
sqrt (3) = tan A
arctan ( sqrt (3) ) = A = 60°
