few_shots: 
Example:
Problem/activity:
Find the general solution for:
$${\mathrm{cos}\left({\pi\over2}+x\right)=\mathrm{tan}{\pi\over4}}$$


Concept/skill: 
Prove the addition and subtraction formulas for sine, cosine, and tangent and use them to solve problems.

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, does the following problem or activity enable students to learn the full intent of the following concept or skill?

shot_info: fl_problem_001894_pos_0

HS_0
standard_description: Use proportional relationships to solve multistep ratio and percent problems. Examples: simple interest, tax, markups and markdowns, gratuities and commissions, fees, percent increase and decrease, percent error.
problem_activity: Task
Lucia uses the picture below to explain the distributive property for the expression (3+1) $\times$ (5+1):
[IMG]
Find (3+1) $\times$ (5+1) using the distributive property.
Explain how Lucia's picture relates to your calculation in (a).
How can Lucia use a picture to find (3-1) $\times$ (5-1) using the distributive property? Explain.


aligns: no