## Reflection: Problem-based Approaches Three Methods of Solving Quadratics and Word Problems - Section 1: Warm Up

This was a great warm up to the day's lesson because it did lead to student debate and conversation.  As I anticipated, many students jumped right from sqrt(-16) to -4.  However, many evaluated this using their calculator and so they noticed an issue when they received an error message.  We had a brief discussion about whether you could take the square root of a negative number.  Most students were able to see why this was not possible.

The conversation about what does this mean was a little more involved.  Students were not sure what the algebra was telling them about this function.  Finally, one student suggested that we graph it (I was glad this came from a student and not from me!)  When we did, I asked student to look at the graph and think about what it meant without discussing it yet.  I wanted to make sure that all students had the opportunity to process what they were seeing.  After a short time, I let students discuss why they thought the graph reflected their algebra.

# Three Methods of Solving Quadratics and Word Problems

Lesson 13 of 21

## Big Idea: The structure of a quadratic equation can help students determine how to solve the equation.

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### James Bialasik

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