Reading up on attack speed calculations for World of Warcraft I noticed that the formula for attack speed is:
Attack_speed = "current attack speed" / (("Percent increase or decrease" / 100) + 1 )
So with a weapon of speed 1.8 and activating a 40% attack speed buff for example we would have:
Attack_speed = 1.8 / ( (40 / 100) + 1 ) = 1.2857
So I am just wondering why is there a +1 in the formula. Logically I would assume that one would calculate the attack speed like this:
Attack_speed = 1.8 - (1.8 * (40 / 100)) = 1.08
Which is just subtracting the 40% of 1.8 from 1.8, which is how one would normally calculate a percentage in math. Is this just by design or is there some logic to this?