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: Compute unit rates associated with ratios of fractions, including ratios of lengths, areas and other quantities measured in like or different units. For example, if a person walks 1/2 mile in each 1/4 hour, compute the unit rate as the complex fraction 1/2/1/4 miles per hour, equivalently 2 miles per hour.
problem_activity: Task
Rubi was paid \$24 to sweep 4 walks. Which of the following can be represented by an equivalent ratio? Explain your thinking.
\$6 to sweep 1 walk
\$12 to sweep 3 walks
\$30 to sweep 5 walks
Anthea hiked 6 miles in 2 hours. Which of the following can be represented by an equivalent ratio? Explain your thinking.
4 miles in 1 hour
12 miles in 4 hours
9 miles in 3 hours


aligns: no