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, assess whether the following problem or activity is 'aligned' with the given Common Core standard in Mathematics.

shot_info: fl_problem_001894_pos_0

HS_0
standard_description: Apply and extend previous understandings of multiplication to multiply a fraction or whole number by a fraction.
problem_activity: Problem 1
Solve. Show or explain your work.
a.
$${{2\over3} }$$
of
$${{4\over5}}$$
b.
$${{4\over9}}\times \frac{5}{8}$$
Problem 2
A farmer’s land measures
$${{7\over8}}$$
of a mile long and
$${{4\over5}}$$
of a mile wide. What is the area, in square miles, of the farmer’s land?


aligns: yes