Use linear approximation, i. e. the tangent line, to approximate √ 16.2 as follows: let f ( x ) = √ x . find the equation of the tangent line to f ( x ) at x = 16 l ( x ) = using this, we find our approximation for √ 16.2 is note: for this part, give your answer to at least 9 significant figures or use an expression to give the exact answer. get : video