Step 1: Understand that tan^(-1)(x) is the angle whose tangent is x.
Step 2: Draw a right triangle where the angle is theta, and the opposite side is x and the adjacent side is 1 (since tan(theta) = opposite/adjacent = x/1).
Step 3: Use the Pythagorean theorem to find the hypotenuse. The hypotenuse is √(opposite^2 + adjacent^2) = √(x^2 + 1^2) = √(x^2 + 1).
Step 4: Now, find sin(theta). Sin is defined as opposite/hypotenuse, so sin(tan^(-1)(x)) = x / √(x^2 + 1).
Step 5: Simplify the expression to get sin(tan^(-1)(x)) = x / √(1 + x^2).
