Yefim S. answered 02/20/21
Math Tutor with Experience
sin(arctan(2x) - arccos(x)); Let α = arctan(2x) and β = arccos(x).
Then we have: sin(α - β) = sinαcosβ - cosαsinβ;
tanα = 2x; cosβ = x; sinβ = √1 - x2;
cosα = 1/√1 + 4x2; sinα = 2x/√1 + 4x2;
sin(arctan(2x) - arccos(x)) = 2x2/√1 + 4x2 - √1 - x2/√1 + 4x2 (2x2 - √1 - x2)/√1 + 4x2