few_shots: 
Example 1:
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.

Example 2:
Concept/skill: 
Solve quadratic equations in one variable.

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


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

Example 3:
Concept/skill: 
Construct a tangent line from a point outside a given circle to the circle.

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 $P$.


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, 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

im_task_000870_pos_0

HS_1

im_task_001160_neg_0

HS_2
standard_description: Understand that a function from one set (called the domain) to another set (called the range) assigns to each element of the domain exactly one element of the range. If f is a function and x is an element of its domain, then f(x) denotes the output of f corresponding to the input x. The graph of f is the graph of the equation y = f(x).
problem_activity: Activity
This practice activity is similar to the last activity in the associated Algebra 1 lesson, except that students are asked to find specific information about the contexts before being asked to compare them.
To give students a greater opportunity to communicate their thinking verbally and listen to the reasoning of others, we recommend assigning each student to either work on function
\(m\)
or
\(p\)
for the first question, and then get together in groups of 2–4 to tackle the remaining questions.
Launch
Arrange students in groups of 2. In each group, one partner completes the first question for function
\(m\)
, and the other partner for function
\(p\)
. Then, partners should work together using the information they found in the first question to complete the remaining questions.
It’s a judgment call about whether to ask students to find the maximum of function
\(m\)
without a graphing calculator or provide access to graphing calculators. In the associated Algebra 1 lessons, there are times when students are asked to answer such a question without graphing.
Student Facing
Two objects are thrown into the air. The height of object M in meters is modeled by the function
\(m(x)=(5+10x)(1.5-x)\)
with
\(x\)
representing time in seconds. The height of object P in meters is modeled by the function
\(p\)
, represented by the graph.
[IMG]
For each object, determine:
the time at which the object hit the ground
the height from which the object was thrown
the maximum height of the object
the time at which the object reached its maximum height
Which object was launched from a greater height? Explain your reasoning.
Which object hit the ground first? Explain your reasoning.
Which object reached a greater maximum height? Explain your reasoning.
Student Response
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Activity Synthesis
Much of the conversation will take place within groups. Time permitting, invite students to create a visual display of their solutions and explanations. Give students an opportunity to review other groups’ work, and time to revise and refine their own work. If desired, select a few exemplary visual displays to keep posted in the classroom to support students in later lessons.


aligns: no