MCF 3M1
Date ___________
Lesson 3: Solving Quadratic Equations by Factoring
Yesterday we learnt that a quadratic equation can be solved by graphing or
factoring. Finding the solution to a quadratic equation is the same as finding the
____________, ______________ or ________________.
To solve quadratic equations by factoring, we MUST follow the following steps:
1.
2.
3.
4.
Rearrange equation in the form of ax 2  bx  c  0
Common Factor
Follow your steps when factoring simple or complex trinomials
Use the “zero product property” to solve for the roots
Examples: Solve by Factoring
1.
x 2  2 x  24  0
2.
9 x 2  25  0
3.
4 x 2  20 x  25
4.
x 2  7 x  10  28
MCF 3M1
5.
Date ___________
2( x  3) 2  5( x  3) Verify your solution
LS
RS
6. The path a dolphin travels when it rises above the water can be modeled by the
function h(d )  0.2d 2  2d , where h (d ) is the height of the dolphin above the
water’s surface and d is the horizontal distance from the point where the
dolphin broke the water’s surface, both in feet. When will the dolphin reach a
height of 1. feet?