l>
    <div class="sage"><script type="text/x-sage">
var('x,y,z,t')
solve([x+y+z==3, 2*x-y==4,x==t], (x,y,z))
</script></div>    
  </div>
</section>
  <section>
  <h1>Higher Order Approximations</h1>
  <p>When you ask a calculator to
  tell you what $e^{0.1}$ means, your calculator uses an extension
  of differentials to give you an approximation. The calculator
  only uses polynomials (multiplication and addition) to give you
  an answer. This same process is used to evaluate any function
  that is not a 