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The exponential function

The exponential function is the function equation

figure
figure
equation
equation
equation
equation

Properties:

  1. equation
  2. equation
  3. equation
  4. equation

the exponential function is bijective and invertible

If a,b(0,+) and x,yRa, b\in(0,+\infty) \text{ and } x, y\in \mathbb{R}, then:

1. equation 2. equation 3. equation

4. equation 5. equation

figure

Try it

The exponential function, with the base a on a slider.

The chapter states that the function is strictly increasing when a > 1 and strictly decreasing when 0 < a < 1. Drag a through 1 and watch the curve turn over. At exactly a = 1 it flattens into the constant line y = 1, which is why the definition excludes it.

Whatever a is, the curve passes through (0, 1) and never touches the x-axis.