Presentation on theme: "U4-S3-L3 Solve Quadratics by Square Roots Essential Question: How do you solve a quadratic equation by graphing and square roots?"— Presentation transcript:
U4-S3-L3 Solve Quadratics by Square Roots Essential Question: How do you solve a quadratic equation by graphing and square roots?
Solving To solve a quadratic function, look for the x- intercepts: where the parabola intersects the x-axis. Words for solutions to quadratics: 1) zeros Words for solutions to quadratics: 1) zeros 2) roots 2) roots 3) solutions 3) solutions 4) answers 4) answers 5) x-intercepts 5) x-intercepts
Solutions A zero is just like looking for an x-intercept A quadratic will only have 2, 1, or no zeros.
Main Idea Some quadratic equations are missing an a, b, or c value, and graphing can be difficult. You can solve by square roots. Remember, you cannot take the square root of a negative number. However, there are 2 answers to a square root: the positive and negative root.
Vocabulary Perfect Square Perfect Square: A number whose square roots are integers. Square Root Square Root: one of the equal factors that makes up the square. – Uses the “√ ” symbol – Has a positive and negative solution Principle Square Root Principle Square Root: the positive square root
Squares & Square Roots Squares and square roots are inverse operations because they are opposites.
Solving by Square Roots To solve by square root: 1)Quadratic does NOT have a b. Only ax 2 + c = 0 2)Isolate the variable by inverse operations. 3)Square root both sides, if possible. 4)Write solution as + and – answer.
Approximating Solutions When factoring doesn’t work, and it isn’t a perfect square, then you must round your answer.
Summary Answer the essential question in detailed, complete sentences. How do you solve a quadratic equation by graphing and square roots? Write 3-5 study questions in the left column to correspond with the notes.