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: Multiply one-digit whole numbers by multiples of 10 in the range 10–90 (e.g., 9 × 80, 5 × 60) using strategies based on place value and properties of operations.
problem_activity: Task
California is in the fifth year of a drought. Towns have been asked to decrease water use across the state. The graph below shows the water storage in Lake Sonoma, a reservoir in Northern California from 1988, shortly after it was first filled, until February 1, 2015.
What questions do you have looking at the graph?
Describe some of the features of the graph.
What might explain these features?  (Consider data collection, weather events and reservoir management decisions.)
Based on the given information, should the region that depends on Lake Sonoma for water use implement additional water conservation measures?
[IMG]


aligns: no