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: Use similar triangles to explain why the slope m is the same between any two distinct points on a non-vertical line in the coordinate plane; derive the equation y = mx for a line through the origin and the equation y = mx + b for a line intercepting the vertical axis at b.
problem_activity: Task
DVDs can be made in a factory in New Mexico at the rate of 20
DVDs per \$3, but the factory costs \$80,000 to build.
If they make 1 million DVDs, what is the unit cost per
DVD?
DVDs can be made in a factory in Colorado at the rate of 10
DVDs per \$1.50, but the factory costs \$100,000 to build.
If they make 1 million DVDs, what is the unit cost per
DVD?
How much can a buyer save on a million DVDs by buying
DVDs from  New Mexico instead of DVDs from Colorado?
Find an equation for the cost of making $x$ number of DVDs
in the factory in New Mexico.
Find an equation for the cost of making $x$ number of DVDs
in the factory in Colorado.


aligns: yes