title: Approximate e^x
body: <p>I'd like to approximate the <strong>e<sup>x</sup></strong> function.</p>
  
  <p>Is it possible to do so using multiple splines type based approach? i.e between <strong>x<sub>1</sub></strong> and <strong>x<sub>2</sub></strong>, then </p>
  
  <blockquote>
    <p><strong>y<sub>1</sub> = a<sub>1</sub>x + b<sub>1</sub></strong>, between x<sub>2</sub> and x<sub>3</sub>, </p>
  </blockquote>
  
  <p>then </p>
  
  <blockquote>
    <p><strong>y<sub>2</sub> = a<sub>2</sub>x + b<sub>2</sub></strong></p>
  </blockquote>
  
  <p>etc</p>
  
  <p>This is for dedicated fpga hardware and not a general purpose CPU. As such I need to create the function myself. Accuracy is much less of a concern. Furthermore I can't really afford more than one multiplication circuit and/or multiple shifts/adders. Also I want something much smaller than a CORDIC function, in fact size is critical.</p>