Answer:
steps below
Step-by-step explanation:
Are you going to solve the value of A or just a proof the equation
cos 2A = cos² A - sin² A
2cos²A-cos2A-1 = 2cos²A - (cos² A - sin² A) - 1 = cos² A + sin² A - 1
2cos²A-cos2A-1 = 1 - 1 = 0
A: 90° or 270° or 450° .....
6(x+1)+48°=180°
6x+6+48=180
6x+54=180
6x=126
x=21°. Hope it help!
Any perpendicular line has a negative reciprocal slope. So your slope would be 2. The. You would have the equation : y=2x+b. You would then replace the coordinate (5,6) with x and y on your line to solve for b. Your equation would be : y=2x-4
X = number of cds on the rack
x + 7 = 30
x = 30 - 7
x = 23 <== so there are currently 23 cds on the rack
