Difference between revisions of "Available Functions"
Jump to navigation
Jump to search
(Removed math tags since they don't seem to be working correctly.) 
(Added some structure.) 

Line 40:  Line 40:  
====Mathematical Functions Available In WeBWorK==== 
====Mathematical Functions Available In WeBWorK==== 

−  +  Unless otherwise specified, all of the functions listed below are enabled by default. However, sometimes one or more of these functions is disabled for 

−  instructor wants you to calculate the answer by some means other than just using the function. 
+  a particular WeBWorK problem because the instructor wants you to calculate the answer by some means other than just using the function. 
+  * sqrt( ) 

* abs( ) The absolute value 
* abs( ) The absolute value 

−  * cos( ) Note: cos( ) uses radian measure 

+  
−  * sin( ) Note: sin( ) uses radian measure 

+  =====Exponential and Logarithmic Functions===== 

−  * tan( ) Note: tan( ) uses radian measure 

+  
−  * sec( ) Note: sec( ) uses radian measure 

+  
−  * cot( ) Note: cot( ) uses radian measure 

−  * csc( ) Note: csc( ) uses radian measure 

* exp( ) The same function as e^x 
* exp( ) The same function as e^x 

* log( ) This is usually the natural log but your professor may have redined this as log to the base 10 
* log( ) This is usually the natural log but your professor may have redined this as log to the base 10 

* ln( ) The natural log 
* ln( ) The natural log 

* logten( ) The log to the base 10 
* logten( ) The log to the base 10 

+  
+  =====Trigonometric Functions===== 

+  
+  '''Note''': All of the trigonometric functions use '''radian''' measure. 

+  
+  * cos( ) 

+  * sin( ) 

+  * tan( ) 

+  * sec( ) 

+  * cot( ) 

+  * csc( ) 

+  
* arcsin( ) 
* arcsin( ) 

* asin( ) or sin^1() Another name for arcsin 
* asin( ) or sin^1() Another name for arcsin 

Line 66:  Line 77:  
* arccsc( ) 
* arccsc( ) 

* acsc( ) or csc^1() Another name for arccsc 
* acsc( ) or csc^1() Another name for arccsc 

+  
+  =====Hyperbolic Trig Functions===== 

+  
* sinh( ) 
* sinh( ) 

* cosh( ) 
* cosh( ) 

Line 84:  Line 98:  
* arccoth( ) 
* arccoth( ) 

* acoth( ) or coth^1() Another name for arccoth 
* acoth( ) or coth^1() Another name for arccoth 

−  * sqrt( ) 

+  
−  * n! (n factorial  defined for n greater than or equal to 0. 

+  =====Other Functions===== 

−  * These functions may not always be available for every problem. 

+  
−  ** sgn( ) The sign function, either 1, 0, or 1 

+  * n! (n factorial  defined for nonnegative integers.) 

−  ** step( ) The step function (0 if x < 0, 1 if x is greater than or equal to 0.) 

+  * fact(n) (another name for n!) 

−  +  * sgn(n) The sign function, either 1 (if n < 0), 0 (if n=0), or 1 (if n>0) 

+  * step(x) The step function (0 if x < 0, 1 if x is greater than or equal to 0.) 

+  
+  The following functions are not enabled by default: 

+  
** P(n,k) = n*(n1)*(n2)...(nk+1) the number of ordered sequences of k elements chosen from n elements 
** P(n,k) = n*(n1)*(n2)...(nk+1) the number of ordered sequences of k elements chosen from n elements 

−  ** C(n,k) = "n choose k" the number of unordered 
+  ** C(n,k) = "n choose k" the number of unordered sets of k elements chosen from n elements 
+  
+  
[[Category:HelpFiles]] 
[[Category:HelpFiles]] 

[[Category:Students]] 
[[Category:Students]] 
Revision as of 13:21, 29 October 2009
Contents
Mathematical Symbols Available In WeBWorK
 + Addition
  Subtraction
 * Multiplication can also be indicated by a space or juxtaposition, e.g. 2x, 2 x or 2*x, also 2(3+4).
 / Division
 ^ or ** You can use either ^ or ** for exponentiation, e.g. 3^2 or 3**2
 Parentheses: ()  You can also use square brackets, [ ], and braces, { }, for grouping, e.g. [1+2]/[3(4+5)]
Syntax for entering expressions
 Be careful entering expressions just as you would be careful entering expressions in a calculator.
 Use the "Preview Button" to see exactly how your entry looks. E.g. to tell the difference between 1+2/3*4 and [1+2]/[3*4] click the "Preview Button".
 Sometimes using the * symbol to indicate mutiplication makes things easier to read. For example (1+2)*(3+4) and (1+2)(3+4) are both valid. So are 3*4 and 3 4 (3 space 4, not 34) but using a * makes things clearer.
 Use ('s and )'s to make your meaning clear. You can also use ['s and ]'s and {'s and }'s.
 Don't enter 2/4+5 (which is 5.5) when you really want 2/(4+5) (which is 2/9).
 Don't enter 2/3*4 (which is 8/3) when you really want 2/(3*4) (which is 2/12).
 Entering big quotients with square brackets, e.g. [1+2+3+4]/[5+6+7+8], is a good practice.
 Be careful when entering functions. It's always good practice to use parentheses when entering functions. Write sin(t) instead of sint or sin t even though WeBWorK is smart enough to usually accept sin t or even sint. For example, sin 2t is interpreted as sin(2)t, i.e. (sin(2))*t so be careful.
 You can enter sin^2(t) as a short cut although mathematically speaking sin^2(t) is shorthand for (sin(t))^2(the square of sin of t). (You can enter it as sin(t)^2 or even sint^2, but don't try such things unless you really understand the precedence of operations. The "sin" operation has highest precedence, so it is performed first, using the next token (i.e. t) as an argument. Then the result is squared.) You can always use the Preview button to see a typeset version of what you entered and check whether what you wrote was what you meant. :)
 For example 2+3sin^2(4x) will work and is equivalent to 2+3(sin(4x))^2 or 2+3sin(4x)^2. Why does the last expression work? Because things in parentheses are always done first [ i.e. (4x)], next all functions, such as sin, are evaluated [giving sin(4x)], next all exponents are taken [giving sin(4x)^2], next all multiplications and divisions are performed in order from left to right [giving 3sin(4x)^2], and finally all additions and subtractions are performed [giving 2+3sin(4x)^2].
 Is 5^2 positive or negative? It's negative. This is because the square operation is done before the negative sign is applied. Use (5)^2 if you want to square negative 5.
 When in doubt use parentheses!!! :)
 The complete rules for the precedence of operations, in addition to the above, are
 Multiplications and divisions are performed left to right: 2/3*4 = (2/3)*4 = 8/3.
 Additions and subtractions are performed left to right: 12+3 = (12)+3 = 2.
 Exponents are taken right to left: 2^3^4 = 2^(3^4) = 2^81 = a big number.
 Use the "Preview Button" to see exactly how your entry looks. E.g. to tell the difference between 1+2/3*4 and [1+2]/[3*4] click the "Preview Button".
Mathematical Constants Available In WeBWorK
 pi This gives 3.14159265358979, e.g. cos(pi) is 1
 e This gives 2.71828182845905, e.g. ln(e*2) is 1 + ln(2)
Scientific Notation Available In WeBWorK
 2.1E2 is the same as 210
 2.1E2 is the same as .021
Mathematical Functions Available In WeBWorK
Unless otherwise specified, all of the functions listed below are enabled by default. However, sometimes one or more of these functions is disabled for a particular WeBWorK problem because the instructor wants you to calculate the answer by some means other than just using the function.
 sqrt( )
 abs( ) The absolute value
Exponential and Logarithmic Functions
 exp( ) The same function as e^x
 log( ) This is usually the natural log but your professor may have redined this as log to the base 10
 ln( ) The natural log
 logten( ) The log to the base 10
Trigonometric Functions
Note: All of the trigonometric functions use radian measure.
 cos( )
 sin( )
 tan( )
 sec( )
 cot( )
 csc( )
 arcsin( )
 asin( ) or sin^1() Another name for arcsin
 arccos( )
 acos( ) or cos^1() Another name for arccos
 arctan( )
 atan( ) or tan^1() Another name for arctan
 arccot( )
 acot( ) or cot^1() Another name for arccot
 arcsec( )
 asec( ) or sec^1() Another name for arcsec
 arccsc( )
 acsc( ) or csc^1() Another name for arccsc
Hyperbolic Trig Functions
 sinh( )
 cosh( )
 tanh( )
 sech( )
 csch( )
 coth( )
 arcsinh( )
 asinh( ) or sinh^1() Another name for arcsinh
 arccosh( )
 acosh( ) or cosh^1()Another name for arccosh
 arctanh( )
 atanh( ) or tanh^1()Another name for arctanh
 arcsech( )
 asech( ) or sech^1()Another name for arcsech
 arccsch( )
 acsch( ) or csch^1() Another name for arccsch
 arccoth( )
 acoth( ) or coth^1() Another name for arccoth
Other Functions
 n! (n factorial  defined for nonnegative integers.)
 fact(n) (another name for n!)
 sgn(n) The sign function, either 1 (if n < 0), 0 (if n=0), or 1 (if n>0)
 step(x) The step function (0 if x < 0, 1 if x is greater than or equal to 0.)
The following functions are not enabled by default:
 P(n,k) = n*(n1)*(n2)...(nk+1) the number of ordered sequences of k elements chosen from n elements
 C(n,k) = "n choose k" the number of unordered sets of k elements chosen from n elements