Which statement about a quadratic equation is true?

Which statement about a quadratic equation is true?

• A. It has degree 3
• B. It represents a straight line
• C. It can be solved only by graphing
• D. It has degree 2 and graphs as a parabola

Answer: (D)

A quadratic equation is a polynomial where the highest power of the variable is 2. That makes it degree two, and its graph is a parabola. This combination—degree 2 with a parabolic graph—best describes a quadratic equation. The other statements don’t fit: a degree-3 polynomial is a cubic, not quadratic; a straight line comes from degree 1; and quadratic equations can be solved by algebraic methods such as factoring, completing the square, or the quadratic formula, not only by graphing.

A quadratic equation is a polynomial where the highest power of the variable is 2. That makes it degree two, and its graph is a parabola. This combination—degree 2 with a parabolic graph—best describes a quadratic equation. The other statements don’t fit: a degree-3 polynomial is a cubic, not quadratic; a straight line comes from degree 1; and quadratic equations can be solved by algebraic methods such as factoring, completing the square, or the quadratic formula, not only by graphing.