Design the test cases and test the program of Quadratic Equation problem by using Equivalence Class testing

In Equivalence class testing, we require to separate valid input and output domain from invalid inputs and outputs. And then after test cases are formed.

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.