Identify expression: Identify the expression to simplify.We need to find the value of 2tan−1(21).
Apply double angle formula: Apply the formula for the double angle of tangent.Using the identity for double angles, tan(2a)=(1−tan2(a))2tan(a), where a=tan−1(21).
Calculate tan−1(21): Calculate tan−1(21).Let a=tan−1(21), then tan(a)=21.
Substitute into formula: Substitute tan(a) into the double angle formula.tan(2a)=1−(21)22×(21)=1−411=431=34.
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