In triangle problem, we require to identify output and input domain.

Output Domain:

O₁ = Not a triangle, when any of the sides is greater than the sum of the other
O₂ = Equilateral Triangle
O₃ = Isosceles Triangle
O₄ = Scalene Triangle

Input Domain:
I₁ = { 0< a <= 10 }
I₂ = { a<0 }
I₃ = { a>10 }
I₄ = { 0< b <= 10 }
I₅= { b<0 }
I₆ = { b>10 }
I₇ = { 0< c <= 10 }
I₈ = { c<0 }
I₉ = { c>10 }

Further, on the basis of sides equality and whether the sum of the two sides are equal or greater, we can create classes.
I₁₀ = { a=b=c }
I₁₁ = { a=b, b!=c }
I₁₂ = { b=c, c!=a }
I₁₃ = { a=c, c!=b }
I₁₄ = { a!=b!=c }
I₁₅ = { a+b = c }
I₁₆ = { a+b < c }
I₁₇ = { b+c = a }
I₁₈ = { b+c < a }
I₁₉ = { c+a = b }
I₂₀ = { c+a >b }
There are 4 possible outcomes and 20 possible input classes, in total 24 test cases to test.

Here are the test cases and program tested results.

You can check out the “previous date problem” program along with its tested test cases here.

First let’s identify the output domain for the previous date problem.

O₁ = Previous date
O₂ = Invalid date

Coming to Input domain,

I₁ = {1 <= date <=31 }
I₂ = {date<0 }
I₃ = {date>31}
I₄ = {1<= month <=12 }
I₅ = {month<1 }
I₆ = {month >31}
I₇ = {2000<= year <=2050}
I₈ = {year<2000 }
I₉ = {year>2050}

In this problem, we can clearly see 2 test cases for output and 9 test cases for input are made.

Program:

Here are the Quadratic Equation problem program and its tested outputs.

Equivalence Class testing

Considering Output domain first,

O₁ = Not a quadratic equation when a = 0
O₂ = Real roots,  b² – 4ac > 0
O₃ = Equal roots,  b² – 4ac = 0
O₄ = Imaginary roots,  b² – 4ac < 0
Now Input domain,
I₁ = { 0< a <= 10 }
I₂ = { a<0 }
I₃ = { a>10 }
I₄ = { 0< b <= 10 }
I₅= { b<0 }
I₆ = { b>10 }
I₇ = { 0< c <= 10 }
I₈ = { c<0 }
I₉ = { c>10 }
I₁₀ = { a= 0 }
In total there are 14 test cases, 4 for possible outputs and 10 for different different combinations of input.

Input and output domains	a	b	c	Expected Output	Program Output	Tested Outcome
O1	0	5	5	Not Quadratic	Not Quadratic	Pass
O2	1	5	5	Real	Real	Pass
O3	5	5	5	Imaginary	Imaginary	Pass
O4	5	10	5	Equal	Equal	Pass
I1	5	5	5	Imaginary	Imaginary	Pass
I2	-1	5	5	Invalid Input	Invalid Input	Pass
I3	11	5	5	Invalid Input	Invalid Input	Pass
I4	5	5	5	Imaginary	Imaginary	Pass
I5	5	-1	5	Invalid Input	Invalid Input	Pass
I6	5	11	5	Invalid Input	Invalid Input	Pass
I7	5	5	5	Imaginary	Imaginary	Pass
I8	5	5	-1	Invalid Input	Invalid Input	Pass
I9	5	5	11	Invalid Input	Invalid Input	Pass
I10	0	5	5	Not Quadratic	Not Quadratic	Pass

In given table, first four are from output domain and other are from inputs.