What is the definition of mathematic

the abstract science of number, quantity, and space, either as abstract concepts ( pure mathematics ), or as applied to other disciplines such as physics and engineering ( applied mathematics ).

  Option A is the correct answer

Step-by-step explanation:

For a perfect square quadratic equation discriminant b²-4ac is zero.

Option A

    x²-6x+9, a = 1 , b = -6 and c = 9

    b²-4ac = 36 - 4 x 1 x 9 = 0

    Correct answer.

Option B

    x²-2x+4, a = 1 , b = -2 and c = 4

    b²-4ac = 4 - 4 x 1 x 4 = -12

    Wrong answer.

Option C

    x²+5x+10, a = 1 , b = 5 and c = 10

    b²-4ac = 25 - 4 x 1 x 10 = -15

    Wrong answer.

Option D

    x²+4x+16, a = 1 , b = 4 and c = 16

    b²-4ac = 16 - 4 x 1 x 16 = -48

    Wrong answer.