Help in Entering Functions

Entering Basic Functions

Mathematical Form
Input (Keyboard) Form
  2 x3x2 + 1
2 x^3 -x^2 + 1
(5 x – 1)2(1 – x)3
(5x-1)^2(1-x)^3 or ((5x-1)^2)(1-x)^3
(x – 1)4/3

Always use x or X as your variable.

To enter a function, you can use your computer keyboard interchangably with one of the calculator keypads.

You can use parentheses, ( ), square brackets, [ ], or curly braces, { }, to group terms.

Terms in x may be entered as numbers (coefficients) times powers in x. You can use "*" for multiplication, or in the case of a number times x, you can abbreviate, say,"3*x" by "3x" but not "x3"; also, "x*x" cannot be abbreviated to "xx".

Coefficients may be entered as integers (like 2 or –3), rational numbers (ratios of integers, like (1/2) or (–5/4)), or decimals (like 1.52 or –7.6). We automatically convert all decimals to their rational number equivalents (for example, 1.52 = 38/25). Fractional powers can be entered using parentheses, as in 3^(1/2) or x^(-1/3).

Use pi for π (approximately 3.14) and e for the base e (approximately 2.72) of natural logarithms.

Entering Intermediate and Advanced Functions

Mathematical Form
Input (Keyboard) Form
log(x) or ln(x) or log(e,x)
tan x
sin 2πx
sin(2pix) or sin(2pi*x)

When entering any function with an abbreviated name, like sin for sine, the argument (term in x) following the name needs to be enclosed in paired parentheses. So, "sinx" is incorrect, as is "sin(x", but "sin(x)" is correct.

Logarithmic Functions. Logarithmic functions can be entered with one argument, as in log(x), or two arguments, as in log(b, x), where b is the base, b > 0, b ≠ 1. When only one argument is used, it refers to the logarithm to the base e, so log(x)=log(e, x), where e≈ 2.72 is the base of the natural logarithms. The natural logarithm can also be entered as ln(x). Exponential functions can be entered conveniently using the power symbol, as in e^x or 2^(x^2–1).

More Information

For further illustrations of valid input, see how functions are entered in the Polynomial Function Examples .




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United States Patent Numbers 7,432,926, 7,595,801, & 7,889,199.
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