few_shots: 
Example 1:
Problem/activity:
Find the general solution for:
$${\mathrm{cos}\left({\pi\over2}+x\right)=\mathrm{tan}{\pi\over4}}$$


Concept/skill: 
Understand that by similarity, side ratios in right triangles are properties of the angles in the triangle, leading to definitions of trigonometric ratios for acute angles.

Answer: 
No. This problem does not directly teach how side ratios in right triangles lead to definitions of trigonometric ratios. Instead, it involves solving a trigonometric function.

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 following problem or activity enable students to learn the full intent of the following concept or skill?

shot_info: fl_problem_001894_neg_0

HS_0

im_task_000870_pos_0

HS_1

im_task_001160_pos_0

HS_2
standard_description: (+)Derive the equations of ellipses and hyperbolas given the foci, using the fact that the sum or difference of distances from the foci is constant.
problem_activity: Activity
Continuing the thinking from the warm-up, students now compare three functions whose graphs are vertical translations from one another and generalize their observations of the graphs and data tables into equations where one function is defined in terms of another.
Monitor for students making connections between representations as they write an equation for
\(g(x)\)
in terms of
\(h(x)\)
. For example, students may:
compare the graphs of
\(g\)
and
\(h\)
, perhaps sketching them on the same axes and then measuring the vertical distance between them
calculate the difference between the outputs from the table
combine the equation they wrote for
\(g(x)\)
in terms of
\(f(x)\)
and
\(h(x)=f(x)-2.5\)
to rewrite
\(g(x)\)
in terms of
\(h(x)\)
Launch
Representation: Internalize Comprehension.
Chunk this task into more manageable parts. Check in with students after the first 2–3 minutes of work time to look for students who notice the constant difference between the outputs of
\(f(x)\)
and
\(g(x)\)
. Check to make sure that students are filling out the
\(g(x)\)
column of the table correctly.
Supports accessibility for: Conceptual processing; Organization
Student Facing
The graph of function
\(g\)
is a vertical translation of the graph of polynomial
\(f\)
.
[IMG]
[IMG]
Complete the
\(g(x)\)
column of the table.
If
\(f(0) = \text-0.86\)
, what is
\(g(0)\)
? Explain how you know.
Write an equation for
\(g(x)\)
in terms of
\(f(x)\)
for any input
\(x\)
.
The function
\(h\)
can be written in terms of
\(f\)
as
\(h(x)=f(x)-2.5\)
. Complete the
\(h(x)\)
column of the table.
| \(x\) | \(f(x)\) | \(g(x)\) | \(h(x)=f(x)-2.5\) |
|-------|----------|----------|-------------------|
|  -4   |    0     |          |                   |
|  -3   |   -5.8   |          |                   |
| -0.7  |    0     |          |                   |
|  1.2  |   -3.3   |          |                   |
|   2   |    0     |          |                   |
Sketch the graph of function
\(h\)
.
[IMG]
Write an equation for
\(g(x)\)
in terms of
\(h(x)\)
for any input
\(x\)
.
Student Response
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Activity Synthesis
A key takeaway from this discussion is that students understand that a vertical translation from one graph to another corresponds to constant differences between the outputs of the functions for the same input. We can then generalize these point by point comparisons using function notation, where adding or subtracting from the output of the function resulting in a vertical translation of its graph.
Select previously identified students to share the connections they made between the representations in the order listed in the Activity Narrative. If time allows and no students used the equations for
\(g(x)\)
and
\(h(x)\)
in terms of
\(f(x)\)
to write a new equation for
\(g(x)\)
in terms of
\(h(x)\)
, invite them to do so now.


aligns: no