**I. Function Keys **

C. Exponential and Logarithmic Keys

1. (10 raised to a power) is a key you can use to raise 10 to a power. Press and then the exponent.

2. (Common log - base 10) takes the logarithm base 10 of any positive number. If you enter a negative expression, the answer will be given in complex form. There is no real number answer. This is shown in the screen in the middle below. If you enter a zero, you will get an error message as shown in the third panel.

3. (natural exponent) will raise the natural exponent e to any real power. Press to access the function.

4. (natural logarithm) will calculate the natural log (log base e) of any nonnegative expression. If you enter a negative expression, the answer will be given in complex form. There is no real number answer. This is shown in the screen in the middle below. If you enter a zero, you will get an error message as shown in the third panel.

5. (square root) will take the square root of a nonnegative number or expression. If the expression is negative, the answer is given in complex form and is not a real number. To access the function, press .

6. (squared) will square an expression.

7. (reciprocal) will take the reciprocal of the expression. Access this function by pressing . You can also take the reciprocal of a value that has already been calculated by accessing after an expression has been calculated and then ENTER.