few_shots: 
Example:
Problem/activity:
Find the general solution for:
$${\mathrm{cos}\left({\pi\over2}+x\right)=\mathrm{tan}{\pi\over4}}$$


Concept/skill: 
Prove the addition and subtraction formulas for sine, cosine, and tangent and use them to solve problems.

Answer: 
Yes. An initial step when solving for x in this problem requires the use of the addition formula for cosine on the left side of the equation.

Now, does the problem or activity shown below enable students to learn the full intent of the following concept or skill?

shot_info: fl_problem_001894_pos_0

HS_0
standard_description: Relate counting to addition and subtraction (e.g., by counting on 2 to add 2).
problem_activity: Narrative
The purpose of this warm-up is for students to subitize or use grouping strategies to describe the number of dots they see and how they see them. Students have an opportunity to notice and make use of structure (MP7) because each dot image builds from the previous one, and students can think about adding on one or rearranging the dots rather than counting.
Launch
Groups of 2
“How many do you see? How do you see them?”
Flash the image.
30 seconds: quiet think time
Activity
Display the image.
“Discuss your thinking with your partner.”
1 minute: partner discussion
Record responses.
Repeat for each image.
Student Facing
How many do you see?
How do you see them?
[IMG]
[IMG]
[IMG]
Student Response
Teachers with a valid work email address can
click here to register or sign in
for free access to Student Response.
Activity Synthesis
“What helped you see how many dots there were each time?” (In the second image I saw 3 and 1 more and I know that is 4. In the last one I saw 2 and 2.)


aligns: no