Download Mathematics and WeBWorK

Mathematics and WeBWorK
Basics
1. Exponents: x2 could be entered as x^2. You want to use the caret symbol for
that, Shift + 6 usually does the trick.
2. Be careful with complicated exponents:
(a) x^2/3 is interpreted as (x2 )/3 which is
x2
3
(b) x^(2/3) is interpreted as x2/3
(c) 2^3*5 is interpreted as 23 · 5 which is the same as (23 ) · 5
(d) 2^(3*5) is interpreted as 23·5
(e) 3x^2 is interpreted as 3 · x2 which is the same as 3 · (x2 )
(f) (3x)^2 is interpreted as (3x)2
(g) 3 + x^2 is interpreted as 3 + x2
(h) (3+x)^2 is interpreted as (3 + x)2
(i) -5^2 is interpreted as −52 which is the same as −(52 ) which equals −25
(j) (-5)^2 is interpreted as (−5)2 which equals 25
3. Roots:
√
(a) x could be entered as sqrt(x)
√
(b) 5 x − 1 could be entered as (x-1)^(1/5), and similarly for all other higher
degree roots.
4. Fractions: be careful to put complicated numerators and denominators in parenthesis:
3
−1
x
x+3
(b) (x+3)/x-1 is interpreted as
−1
x
3
(c) x+3/(x-1) is interpreted as x +
x−1
x+3
(d) (x+3)/(x-1) is interpreted as
x−1
(a) x+3/x-1 is interpreted as x +
5. You can use the pipe symbol or abs function for absolute value.
usually does the trick.
Shift + \
(a) expression |x| could be entered as |x| or abs(x)
(b) expression |x − 3| could be entered as |x-3| or abs(x-3)
6. It is a very good idea to use the Preview Answers button to see how computer
interprets your input first, and only when you see that computer understood you,
submit your answer and get feedback by clicking Submit Answers button.
Special Functions
1. Natural Exponent, ex , could be entered as exp(x).
2. Natural Logarithm, ln x, could be entered as ln(x).
3. WeBWorK always uses radians when calculating values of trigonometric functions. Trigonometric functions could be entered using their common names:
Math version
sin x
cos x
tan x
cot x
WeBWorK version
sin(x)
cos(x)
tan(x)
cot(x)
4. Inverse trigonometric functions are easier to enter with the arc- notation:
Math version
sin−1 x or arcsin x
cos−1 x or arccos x
tan−1 x or arctan x
WeBWorK version
arcsin(x)
arccos(x)
arctan(x)
5. Functions and exponents. You want to be careful when you have a combination
of a special function and multiplication or an exponent in WeBWorK:
(a) sin 2x will be interpreted as [sin(2)] · x
(b) sin (2x) will be interpreted as sin(2x)
(c) sin x^2 will be interpreted as [sin(x)]2
(d) sin (x^2) will be interpreted as sin(x2 )
Essentially, WeBWorK tries to evaluate the value of a function before doing any
other algebraic operations. That’s why sin 2x gets interpreted by WeBWorK as
sine of 2 multiplied by x.
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