This paper introduces a parabolic synthesis methodology for developing approximations of unary functions. Examples are trigonometric functions and logarithms as well as square root and division functions. They are extensively used and specialized for efficient hardware mapped VLSI design. The advantages with the methodology are, short critical path, fast computation and high throughput enabled by a high degree of architectural parallelism. The feasibility of the methodology is shown by developing an approximation of the sine function for implementation in hardware.