Solve by the quadratic formula

Solve by the quadratic formula

Introduction to the Quadratic Formula

  • The quadratic formula is an important and versatile tool for solving quadratic equations.
  • Quadratic equations are of the form ax^2 + bx + c = 0, where a, b, and c are coefficients and x is the unknown variable.
  • The quadratic formula is illustrated as: x = (-b ± sqrt(b^2 - 4ac)) / (2a).

Solving Quadratic Equations by the Quadratic Formula

  • The main advantage of the quadratic formula is that it can solve any quadratic equation, even if it could not be easily factored or simplified by other methods.
  • To find the roots of the quadratic equation using the quadratic formula, carefully input values for a, b, and c into the formula.
  • It’s important to note the “±” symbol in the formula, which means there can be two possible solutions: one using plus (known as the positive root) and one using minus (known as the negative root).
  • When b^2 - 4ac is positive, the quadratic equation will have two real roots.
  • When b^2 - 4ac equals zero, the equation has exactly one real root.
  • When b^2 - 4ac is negative, the equation has two complex roots, and you’ll need knowledge of imaginary numbers to understand these solutions.

Examples

  • For example, let’s use the quadratic equation 3x^2 + 2x - 1 = 0. In this case, a = 3, b = 2, and c = -1
  • Substitute these values into the quadratic formula: x =(-2 ± sqrt((2)^2 - 43(-1))) / (2*3)
  • Simplify the square root: x =(-2 ± sqrt(4 +12)) / 6
  • This leads to x =(-2 ± sqrt(16)) / 6, after simplification, x = -2/3 or 1/2

Conclusion

  • The quadratic formula is very reliable because you can use it to solve any quadratic equation, but it should be used with caution due to potential complexity.
  • The discriminant (b^2 - 4ac) determines the nature of the roots such as real, repeated or complex.
  • Practise is key to mastering this topic, and a solid understanding of the quadratic formula can support your progress in advanced mathematical topics.