Tan 2x - cot x = 0 2tan x / (1 - tan^2 x) - 1/tan x = 0 2tan^2 x - (1 - tan^2 x) = 0 2tan^2 x - 1 + tan^2 x = 0 3tan^2 x - 1 = 0 tan^2 x = 1/3 tan x = + or - 1/√3
The manager multiplied the price by 43%, instead of noticing the words "mark up", which means the price increased by 43 percent and the cost is multiplied by 143/100!
