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: 
Construct a tangent line from a point outside a given circle to the circle.

Answer: 
No. This task does not involve drawing lines that are tangent to circles. The only line that may be drawn is the ray between points P and B.

Now, does the following problem or activity 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_neg_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: Narrative
The purpose of this lesson is for students to solve a Put Together/Take Apart, Both Addends Unknown story problem in the context of putting together pattern blocks (MP2). If students finish early, invite them to find multiple solutions to the story problem.
MLR8 Discussion Supports.
Synthesis: For each decomposition that is shared, invite students to turn to a partner and restate the recorded equation.
Advances: Listening, Speaking
Required Materials
Materials to Gather
10-frames
Connecting cubes or two-color counters
Pattern blocks
Launch
Groups of 2
Give students access to connecting cubes or two-color counters, 10-frames, and pattern blocks.
Read and display the task statement.
“Tell your partner what happened in the story.”
30 seconds: quiet think time
1 minute: partner discussion
Monitor for students who accurately retell the story. Choose at least one student to share with the class.
Reread the task statement.
“Show your thinking using drawings, numbers, words, or objects.”
Activity
2 minutes: independent work time
2 minutes: partner discussion
“If you haven’t already, write an expression to show how many square pattern blocks and triangle pattern blocks Diego used.”
2 minutes: independent work time
Student Facing
Diego built a shape with 10 pattern blocks.
He only used squares and triangles.
How many square pattern blocks did Diego use?
Then how many triangle pattern blocks did Diego use?
Expression: _________________________________
Student Response
Teachers with a valid work email address can
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for free access to Student Response.
Activity Synthesis
Invite students who found different decompositions of 10 to share.
As students share, record each solution with an equation, such as
\(10 = 7 + 3\)
.
“Did _____ and _____ both show what happened in the story? How do you know?” (Yes. They both have 10 pattern blocks, with some triangles and some squares.)
“In the next activity, we will find more ways that we can make shapes with 10 pattern blocks.”


aligns: no