Using quadratic formula to solve quadratic equations

Using quadratic formula to solve quadratic equations

Not sure if you should solve the quadratic equation by factoring or completing the square? No worries. You can always use the quadratic formula. The beauty of the quadratic formula is that it can always give you the answer no matter if the quadratic equations can be factored or not.
Basic Concepts: Quadratic function in general form: y=ax2+bx+cy = ax^2 + bx+c, Shortcut: Vertex formula, Multiplying and dividing radicals
Related Concepts: System of quadratic-quadratic equations, Graphing quadratic inequalities in two variables, Graphing systems of quadratic inequalities, Conics - Parabola

Lessons

Quadratic Formula
For the quadratic equation: ax2+bx+c=0a{x^2} + bx + c = 0
the solutions are: x=−b±b2−4ac2ax = \frac{{ - b\; \pm \;\sqrt {{b^2} - 4ac} }}{{2a}}
  • Introduction
    Solve the equation using the quadratic formula:
    2x2−12x+10=02{x^2} - 12x + 10 = 0
  • 1.
    Solving a quadratic equation with TWO REAL SOLUTIONS
    Solve using the quadratic formula: x2+10x+6=0x^2+10x+6=0
  • 2.
    Solving a quadratic equation with ONE (REPEATED) REAL SOLUTION
    Solve using the quadratic formula: 9x2+25=30x9x^2+25=30x
  • 3.
    Solving a quadratic equation with TWO COMPLEX SOLUTIONS
    Solve using the quadratic formula: −3x2−24x=49-3x^2-24x=49
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20.
Solving Quadratic Equations
20.1
Solving quadratic equations by factorising
20.2
Solving quadratic equations by completing the square
20.3
Using quadratic formula to solve quadratic equations
20.4
The discriminant: Nature of roots of quadratic equations
20.5
Applications of quadratic equations
GCE N(A)-Level Maths
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