few_shots: 
Example 1:
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.

Example 2:
Problem/activity:
Task
Solve the quadratic equation
$$ x^2 = (2x - 9)^2 $$
using as many different methods as possible.


Concept/skill: 
Solve quadratic equations in one variable.

Answer: 
Yes. This task shows one quadratic equation with one variable, x.

Example 3:
Problem/activity:
Task
Suppose $A$ is an angle with vertex $P$, as pictured below:
[IMG]
Draw a circle with center $P$ and with  radius $r \gt 0$.  Explain why the circle
meets each ray of angle $A$ in a single point.  Label these points $Q$ and $R$ respectively.
Draw circles with centers $Q$ and $R$ respectively and radius $r$.  These circles meet at $P$ and a second point to be labelled $B$.
Show that ray $\overrightarrow{PB}$  bisects angle $P$.


Concept/skill: 
Make formal geometric constructions with a variety of tools and methods (compass and straightedge, string, reflective devices, paper folding, dynamic geometric software, etc.). Copying a segment; copying an angle; bisecting a segment; bisecting an angle; constructing perpendicular lines, including the perpendicular bisector of a line segment; and constructing a line parallel to a given line through a point not on the line.

Answer: 
Yes. This task asks students to draw a ray that bisects an angle. The act of drawing circles and rays may involve compass and straightedge or dynamic geometric software.

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

im_task_000870_pos_0

HS_1

im_task_001160_pos_0

HS_2
standard_description: Represent addition and subtraction with objects, fingers, mental images, drawings (Drawings need not show details, but should show the mathematics in the problem. (This applies wherever drawings are mentioned in the Standards.)), sounds (e.g., claps), acting out situations, verbal explanations, expressions, or equations.
problem_activity: Warm-up
The purpose of this warm-up is to reinforce the distinction between statistical and non-statistical questions. Students write a statistical question and articulate why it qualifies as statistical. Students’ explanations should focus on the variability in the data used to answer the question. The context will be used again in the next activity, so this also gets students familiar with the object.
Launch
Arrange students in groups of 3–4. Give students 1 minute of quiet work time. Then, tell students to share their question and reasoning within their group. Tell the groups to decide if each question is statistical or non-statistical. If the group disagrees, discuss the question further and revise it until an agreement is reached.
Student Facing
Clare collects bottle caps and keeps them in plastic containers.
[IMG]
Write one statistical question that someone could ask Clare about her collection. Be prepared to explain your reasoning.
Student Response
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Activity Synthesis
The purpose of the discussion is to ensure students are comfortable constructing statistical and non-statistical questions.
Ask students to share their statistical questions and reasoning. If possible, ask students to refer back to the image as they share. Record and display their responses for all to see.
To involve more students in the conversation, consider asking some of the following questions:
“Were there any questions your group had in common?”
“Were there any questions your group could not agree were statistical? Why?”
“Were there any questions your group decided were non-statistical? What made that question non-statistical?”


aligns: no