Right. My browser didn't play nice with MathML, so I missed about the part where x = 1 (i.e. I couldn't see the "1" :) ) My objection was that a tangent line,

Right. My browser didn't play nice with MathML, so I missed about the part where x = 1 (i.e. I couldn't see the "1" :) ) My objection was that a tangent line, as opposed to a segment, has infinite length. I can draw infinitely many segments tangent to the curve -- and get infinitely many heights for it.