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require 'rubygems'
require 'spec'

def myexp(x, n)
  x ** n
end

describe "the exponentiation function" do
  context "with x^n" do
    it "multiplies x by itself n times" do
      myexp(3, 2).should be_close(9.0, 0.000001)
      myexp(1, 2).should be_close(1.0, 0.000001)
    end
  end
  context "with x^(1/n)" do
    it "draws the n:th root out of x" do
      myexp(9, 1.0/2.0).should be_close(3.0, 0.000001)
      myexp(125, 1.0/3.0).should be_close(5.0, 0.000001)
    end
  end
  context "with x^-n" do
    it "multiplies 1/x by itself n times" do
      myexp(4, -3).should be_close(0.015625, 0.000001)
      myexp(5, -4).should be_close(0.0016, 0.000001)
    end
  end
  context "with x^0" do
    it "returns 1" do
      myexp(3, 0).should be_close(1.0, 0.000001)
      myexp(5, 0).should be_close(1.0, 0.000001)
    end
  end
end