 (General form) where a, b, c are constants.

Note: If a quadratic equation does not have a general form, we can always rewrite it into a general
form.

E.g., We will only consider real number solutions .

Always modify the equation in general form first. Then use one of two methods : 1. Factoring 2. The quadratic formula If the given equation is a rational equation , check the values that make the denominator(s) zero so
that you can eliminate them from the solution.

Factoring Method

Zero product property : ab = 0, where a, b are real a = 0 or b = 0 or both.

Ex.1 (#10) Solve Ex.2 Solve Ex.3 (#16) Solve (x - 3)(1 - x) = 1

Ex.4 (p.142) Solve Square root property: The solutions of x2 = C is (Or one can think this as factoring which gives )

Ex.5 (#34) Solve Quadratic Formula : If ax2 + bx + c = 0, where a ≠ 0, then Sign of b 2 - 4ac Solutions Two distinct real solutions Exactly one real solution No real solutions

Ex.6 (#22) Solve Ex.7 (#24) Solve Applications

Note: There may be solutions to a quadratic equation that are not the solutions to a problem.

Ex.8 (#44) If the pro t from the sale of x units of a product is what level(s) of
production will yield a pro t of \$180?

Ex.9 (#48) A tennis ball is thrown into a swimming pool from the top of a tall hotel. The height of the
ball from the pool is modeled by feet,

where t is the time, in seconds, after the ball is thrown. How long after the ball is thrown is it 4
feet above the pool?

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