## Reflection: Modeling Problem Solving Identities - Section 2: Problem solving

Here is an example of student work. After reviewing this work, I concluded that this student's understanding is at a high level with respect to the CCSS. When looking his work,  I had to review the first step for a few seconds before I was able to follow his reasoning.

In this case, the student worked to the last shown step. Then, he was confused about finishing the identity. At this stage I provided some assistance. I modeled what I do with identities by having the student look back at where he needed to end. I commented "the final expression has only sine and cosine, so we need to get rid of tangent." At this point, the student realized that tan x =sin x/cos x and he finished the problem on his own.

The student also asked whether there were enough steps in his argument for someone to follow.  We talked about writing out reasons to the right to help others. When I questioned the student he could explain each step. I explained that writing the reasons out would help others follow the process. We also looked at his textbook to see how the authors write out explanations beside the solution. Advanced students need to realize that they may need to write out explanations or show more work so other students can follow their reasoning. This will help those students if they take advanced math classes in college.

Modeling: Explaining your reasoning using algebra

# Problem Solving Identities

Unit 9: Trigonometric Identities
Lesson 7 of 14

## Big Idea: Through the use of algebra and known identities other identities can be verified.

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Standards:
Subject(s):
Math, Trigonometric identities
45 minutes

### Katharine Sparks

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