Cos (B+C - A) + cos (C+ A-B) + cos( A+B+C)
= 1 + 4 cos A. cos B. cos C.​

1. what is the formula for finding the vertical distance between two points on a coordinate plane?

Find the greatest common factor of -30x 4 yz 3 and 75x 4 z 2.

Me solve this problem, and someone clearly explain to me how to solve it.1.) use the value of the discriminant to determine if the given trinomials has 2 real solutions, 1 real solution, or no real solutions. a.  x2  − 4x  − 7 = 0b. 4r2  + 11r  − 3 = 0c. 3m2  + 7 = 0d.  t2  + 2t  + 1 = 0