Exponential functions look somewhat similar to functions you have seen before, in that they involve exponents, but there is a big difference, in that the variable is now the power, rather than the base. Previously, you have dealt with such functions as<span> f(x) = x2</span><span>, where the variable </span>x<span> was the base and the number </span>2<span> was the power. In the case of exponentials, however, you will be dealing with functions such as </span><span>g(x) = 2</span>x, where the base is the fixed number, and the power is the variable.
<span>Let's look more closely at the function </span><span>g(x) = 2</span>x<span>. To evaluate this function, we operate as usual, picking values of </span>x<span>, plugging them in, and simplifying for the answers. But to evaluate </span>2x<span>, we need to remember how exponents work. In particular, we need to remember that </span>negative exponents<span> mean "put the base on the other side of the fraction line".
If you need even more help here : </span>http://www.purplemath.com/modules/expofcns.htm
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