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

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


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, determine whether the following problem or activity can enable students to understand the concepts or skills in the provided description.

shot_info: fl_problem_001894_pos_0

HS_0
standard_description: Derive the equation of a parabola given a focus and directrix.
problem_activity: Narrative
The purpose of this activity is for students to learn stage 3 of the Picture Books center. Students look through picture books and notice and describe shapes they see in the pictures.
Required Materials
Materials to Gather
Picture books
Materials to Copy
Picture Books Stage 3 Recording Sheet
Required Preparation
Each group of 2
–
4 needs at least one picture book that shows a variety of shapes throughout the book.
Launch
Groups of 2
Give each student a recording sheet and each group 2
–
4 picture books.
“We are going to learn a new way to do the Picture Books center.”
“Your group will look through picture books and notice and describe shapes you see in the pictures. On your recording sheet, you will each sketch the shape you see, describe it, and name it.”
Activity
10 minutes: partner work time
Monitor for different shapes students notice.
Activity Synthesis
“What shapes did you find most often?”


aligns: no