This topic describes how to enter mathematical and scientific expressions for problems in your edX course.
You might want to enter a mathematical or scientific expression into an assignment in the body of your course, into the edX calculator tool, or into a course discussion.
For assignments in the body of the course and for the calculator tool, you enter plain text, and the edX system then converts your text into numbers and symbols that appear below the response field. For more information, see Entering Math Expressions in Assignments or the Calculator.
For course discussions, you use MathJax to format the text that you type, and the system then converts your text into a mathematical expression. For more information, see Entering Math Expressions in Course Discussions.
EdX has carefully designed assessments that are accessible to screen readers. However, because of a limitation with HTML and screen reader technology, screen readers may not be able to read math problems in edX courses by default.
To access these problems with a screen reader, use one of the following methods.
Your screen reader may use different names for Interactive mode and Reading mode.
For more information about how to make sure that your screen reader reads all available content, see the instructions for your screen reader.
Both the calculator and the response fields in math problems accept a selection of characters that represent numbers, operators, constants, functions, and other mathematical concepts. You might recognize parts of this system if you have used math programs before.
If your course offers the calculator tool, the calculator appears as a small icon on all pages in the body of the course. To open the calculator, select the calculator icon. To close the calculator, select the X that appears when the calculator is open.
The calculator includes an information page that shows an abbreviated version
of the information in this topic. To see the information page, select the
i icon next to the input field.
When you enter your plain text into the calculator or the response field, follow these guidelines.
m*c^2, and instead of
( )) to specify the order of operations and to make your expression as clear as possible. Use curved parentheses (
( )) only. Do not use brackets (
[ ]) or braces (
v_IN-v_OUT. Note, however, that subscripts cannot currently include operators or parentheses.
For more information about the types of characters you can use, see below.
The edX system accepts both constants and metric affixes. Be careful to distinguish between constants and metric affixes. Constants stand alone, while metric affixes must be combined with numbers.
c can be a constant representing the speed of light or a
metric affix meaning “centi”. When you use
c as a metric affix, do not
include a space between
c and the number. When you use
c as a
constant, indicate multiplication explicitly. The following examples show the
0.02(2 multiplied by 0.01)
599584916.0(the speed of light multiplied by 2)
2,000,000(2 multiplied by 1,000,000)
2*M= 2 multiplied by the variable M
You can use the following types of numbers.
The largest number you can use is 1.7977e+308, which is the largest float possible in the Python programming language.
You can enter metric affixes or scientific notation to indicate very large or
very small numbers. For scientific notation, you can type either a caret (^) or
e followed by a number to indicate an exponent. You can use both
positive and negative exponents.
For example, to indicate
0.012, you can enter either of the following
-440,000, you can enter either of the following expressions:
The following table shows how to enter numbers with metric affixes, with
scientific notation, and with
|To enter this number||Use this metric affix||Use this scientific notation||Use this
|0.01||1c (centi)||10^-2||1e-2||1% (percent)|
When you use metric affixes or
e notation, make sure you do not
include spaces between the number and the metric affix or the
You can use several different constants in your mathematical expressions.
When you enter constants multiplied by a number, make sure to
indicate the multiplication explicitly. For example, enter
2*c instead of
-4*i instead of
||The speed of light in m/s (2.998^8)|
||Euler’s number (2.718…)|
||Gravity (9.80 m/s^2)|
||The square root of -1|
||The square root of -1|
||The Boltzmann constant (~1.38^-23 in Joules/Kelvin)|
||The ratio of a circle’s circumference to its diameter (3.14159…)|
||The fundamental charge (~1.602^-19 Coloumbs)|
||The positive difference between 0K and 0°C (273.15)|
To use any of the following Greek letters, type the name of the letter in the calculator or the response field.
To use a function, type the letters that represent the function, and then
surround the expression in that function with parentheses. For example, to
represent the square root of
You can use the following functions.
Trigonometric functions and their inverses, as well as hyperbolic trigonometric functions and their inverses.
Factorials: Enter factorials as
factorial(3). You must use
integers. For example, you cannot enter
A “parallel resistors” operator (
||). For example,
1 || 2 represents
the resistance of a pair of parallel resistors (of resistance 1 and 2 ohms),
evaluating to 2/3 (ohms).
Entering math expressions in course discussions is different from entering math expressions in a math problem or in the calculator. In course discussions, you use MathJax to format the text that you type.
For detailed information about how to enter math expressions in course discussions, see Math Formatting in Course Discussions.