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: Rewrite simple rational expressions in different forms; write a(x)/b(x) in the form q(x) + r(x)/b(x), where a(x), b(x), q(x), and r(x) are polynomials with the degree of r(x) less than the degree of b(x), using inspection, long division, or, for the more complicated examples, a computer algebra system.
problem_activity: Problem 1
Explain how you know the expressions in Column A are equivalent to the expressions in Column B.
{"table": [{"_attributes": {"class": ["table", "table-bordered"], "style": "width:70%"}, "tbody": [{"tr": [{"td": [{"_attributes": {"style": "text-align:center"}, "strong": [{"_value": "Column A"}]}, {"_attributes": {"style": "text-align:center"}, "strong": [{"_value": "Column B"}]}]}, {"td": [{"_attributes": {"style": "text-align:center"}, "span": [{"_attributes": {"class": ["math-tex"]}, "_value": "$${-3(x+4)}$$"}]}, {"_attributes": {"style": "text-align:center"}, "span": [{"_attributes": {"class": ["math-tex"]}, "_value": "$${-3x-12}$$"}]}]}, {"td": [{"_attributes": {"style": "text-align:center"}, "span": [{"_attributes": {"class": ["math-tex"]}, "_value": "$${(4+x)+3}$$"}]}, {"_attributes": {"style": "text-align:center"}, "span": [{"_attributes": {"class": ["math-tex"]}, "_value": "$${x+(4+3)}$$"}]}]}, {"td": [{"_attributes": {"style": "text-align:center"}, "span": [{"_attributes": {"class": ["math-tex"]}, "_value": "$${(x+4)-3}$$"}]}, {"_attributes": {"style": "text-align:center"}, "span": [{"_attributes": {"class": ["math-tex"]}, "_value": "$${-3+(x+4)}$$"}]}]}]}]}]}
Problem 2
Explain the properties of operations that were used to transform
$${a(x-y)}$$
to the equivalent expression,
$${-(ay-ax)}$$
.
Problem 3
If the expression
$${\frac{x}{2} + \frac{3}{4}}$$
is multiplied by
$$4$$
, the expression
$${{2x+3}}$$
results.
Is
$${{2x+3}}$$
an equivalent expression to
$${\frac{x}{2} + \frac{3}{4}}$$
?


aligns: no