few_shots: 
Example:
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.

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
standard_description: Compare properties of two functions each represented in a different way (algebraically, graphically, numerically in tables, or by verbal descriptions). For example, given a linear function represented by a table of values and a linear function represented by an algebraic expression, determine which function has the greater rate of change.
problem_activity: Task
Complete the table. In the third column, show your work as demonstrated. What do you notice about the 3rd column?
| $x$ | $y=2x+5$ | $\Delta y$ |
|-----|----------|------------|
|  1  |    7     |    ----    |
|  2  |    9     | 9 - 7 = 2  |
|  3  |          |            |
|  4  |          |            |
|  5  |          |            |
Complete the table, showing your work as above. What do you notice about the 3rd column? What is the graphical interpretation of this?
| $x$ |    $y=ax+b$    |            $\Delta y$             |
|-----|----------------|-----------------------------------|
|  1  | $a\cdot 1 +b$  |                ---                |
|  2  | $a \cdot 2 +b$ | $a\cdot 2+b - (a\cdot 1 + b) = a$ |
|  3  |                |                                   |
|  4  |                |                                   |
|  5  |                |                                   |
Let $y=ax+b$. Let $x_0$ be any particular $x$-value. Show that if $x_0$ is increased by 1, the corresponding $\Delta y$ is a constant that does not depend on $x_0$. What is this constant?
Does (a) serve as an example of the result in (c) ? Explain.


aligns: no