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: 
Understand that the graph of an equation in two variables is the set of all its solutions plotted in the coordinate plane, often forming a curve (which could be a line).

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


Answer: 
No. This task does not involve an equation in two variables. There is only 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_neg_0

HS_1

im_task_001160_neg_0

HS_2
standard_description: Use trigonometric ratios and the Pythagorean Theorem to solve right triangles in applied problems.
problem_activity: Problem 1
The data table below shows the weight of a typical male greyhound, a breed of dog, during the first 28 months of his life. Graph the corresponding points, then connect the points in the order they are given to form a line graph.
| **           Age (in months)          ** | **           Weight (in pounds)          ** |
|------------------------------------------|---------------------------------------------|
|                    0                     |                      4                      |
|                    4                     |                     30                      |
|                    8                     |                     55                      |
|                    12                    |                     66                      |
|                    16                    |                     69                      |
|                    20                    |                     72                      |
|                    24                    |                     72                      |
|                    28                    |                     72                      |
What do you notice? What do you wonder?
Problem 2
Using the information about a typical male greyhound’s weight from Anchor Task #1, answer the following questions.
How much does a typical male greyhound weigh when he is born?
What does the coordinate pair (12, 66) mean in the context of this graph?
How much weight does the typical male greyhound gain in the first 4 months of his life? How do you know? What about between 4 months and 8 months? How do you know?
How long does it take the typical male greyhound to grow from 55 to 72 pounds?
Challenge: When does the typical male greyhound gain weight the fastest? How do you know? What about the slowest?
Problem 3
Using the information about the typical male greyhound’s weight from Anchor Task #1, answer the following questions.
How heavy do you think a typical male greyhound gets? How do you know from the graph?
At what age do male greyhounds reach their full weight? Why?
How heavy do you think a typical female greyhound gets? Why?


aligns: no