This page exposes the results of running answer tests on STACK test cases. This page is automatically generated from the STACK unit tests and is designed to show question authors what answer tests actually do. This includes cases where answer tests currentl fail, which gives a negative expected mark. Comments and further test cases are very welcome.

## Diff

Test
?
Student response
Opt
Mark
Diff
1/0
3*x^2
-1 STACKERROR_OPTION.
TEST_FAILED
Diff
0
1/0
(x
-1 STACKERROR_OPTION.
TEST_FAILED
The answer test failed to execute correctly: please alert your teacher. Option field is invalid. You have a missing right bracket ) in the expression: (x.
Diff
1/0
3*x^2
x
-1 ATDiff_STACKERROR_SAns.
Diff
0
1/0
x
-1 ATDiff_STACKERROR_TAns.
Diff
0
0
1/0
-1 ATDiff_STACKERROR_Opt.
Basic tests
Diff
3*x^2
3*x^2
x
1 ATDiff_true.
Diff
3*X^2
3*x^2
x
0 ATDiff_var_SB_notSA.
Diff
x^4/4
3*x^2
x
0 ATDiff_int.
It looks like you have integrated instead!
Diff
x^4/4+1
3*x^2
x
0 ATDiff_int.
It looks like you have integrated instead!
Diff
x^4/4+c
3*x^2
x
0 ATDiff_int.
It looks like you have integrated instead!
Diff
y=x^4/4
x^4/4
x
0 ATDiff_SA_not_expression.
Your answer should be an expression, not an equation, inequality, list, set or matrix.
Diff
x^4/4
y=x^4/4
x
0
Diff
y=x^4/4
y=x^4/4
x
0 ATDiff_SA_not_expression.
Your answer should be an expression, not an equation, inequality, list, set or matrix.
Diff
6000*(x-a)^5999
6000*(x-a)^5999
x
1 ATDiff_true.
Diff
5999*(x-a)^5999
6000*(x-a)^5999
x
0
Variable mismatch tests
Diff
y^2-2*y+1
x^2-2*x+1
x
0 ATDiff_var_SB_notSA.
Diff
x^2-2*x+1
y^2-2*y+1
x
0 ATDiff_var_SA_notSB.
Diff
y^2+2*y+1
x^2-2*x+1
z
0 ATDiff_var_notSASB_SAnceSB.
Diff
x^4/4
3*x^2
y
0
Edge cases
Diff
e^x+c
e^x
x
0 ATDiff_int.
It looks like you have integrated instead!
Diff
e^x+2
e^x
x
0 ATDiff_int.
It looks like you have integrated instead!
Diff
n*x^n
n*x^(n-1)
x
-1 ATDiff_STACKERROR_SAns.
TEST_FAILED
n*x^n
(assume(n>0), n*x^(n-1))
x