The graph of a quadratic function f(x) intersects the xaxis at 3 and 5.
What is a possible equation for f(x)?
Work backwards from the xintercepts to arrive at the equation.
x = 3 and x = 5 x + 3 = 0 and x  5 = 0 {added 3 to each side of first equation and added 5 to each side of second equation} (x + 3)(x  5) = 0 {multiplied the two binomials together and set equal to zero} x²  2x  15 = 0 {muliplied the two binomials using FOIL method or distributive property} f(x) = x²  2x  15 {replaced 0 with f(x) to write in function notation} Comments are closed.

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