 Thus both branches of the curve are near to the half vertical line for which "y"=0, but none is near to the negative part of this line.Basically, there is no tangent at the origin in this case, but in some context one may consider this line as a tangent, and even, in algebraic geometry, as a "double tangent".The graph "y" = |"x"| of the absolute value function consists of two straight lines with different slopes joined at the origin.