few_shots: 
Example 1:
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.

Example 2:
Concept/skill: 
Understand that the graph of an equation in two variables is the set of all its solutions plotted in the coordinate plane, often forming a curve (which could be a line).

Problem/activity:
Task
Solve the quadratic equation
$$ x^2 = (2x - 9)^2 $$
using as many different methods as possible.


Answer: 
No. This task does not involve an equation in two variables. There is only one variable, x.

Example 3:
Concept/skill: 
Make formal geometric constructions with a variety of tools and methods (compass and straightedge, string, reflective devices, paper folding, dynamic geometric software, etc.). Copying a segment; copying an angle; bisecting a segment; bisecting an angle; constructing perpendicular lines, including the perpendicular bisector of a line segment; and constructing a line parallel to a given line through a point not on the line.

Problem/activity:
Task
Suppose $A$ is an angle with vertex $P$, as pictured below:
[IMG]
Draw a circle with center $P$ and with  radius $r \gt 0$.  Explain why the circle
meets each ray of angle $A$ in a single point.  Label these points $Q$ and $R$ respectively.
Draw circles with centers $Q$ and $R$ respectively and radius $r$.  These circles meet at $P$ and a second point to be labelled $B$.
Show that ray $\overrightarrow{PB}$  bisects angle $P$.


Answer: 
Yes. This task asks students to draw a ray that bisects an angle. The act of drawing circles and rays may involve compass and straightedge or dynamic geometric software.

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

im_task_000870_neg_0

HS_1

im_task_001160_pos_0

HS_2
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: Problem 1
For Simon’s birthday, he and his family go out to eat at a restaurant.
a.   The amount of tax is $3.40, which is 5% of the food bill. How much was the food bill not including the tax?
b.   If Simon wants to leave a 20% tip on the amount of the food bill before tax, how much should he leave for a tip?
c.   What is Simon’s total bill including tax and tip? What percent of the food bill is this?
Problem 2
Emily has a coupon for 20 percent off of her purchase at the store. She finds a backpack that she likes on the discount rack. Its original price is $60, but everything on the rack comes with a 30 percent discount.
Emily says, “
Thirty percent and twenty percent make fifty percent, so it will cost $30.
”
Is Emily correct? Explain your reasoning. In your explanation, if you disagree with Emily, find the price she will pay for the backpack.
Problem 3
In order to make money, a store marks up its prices by 25% from the warehouse prices. Let
$$p$$
represent the price at which the store gets its merchandise from the warehouse, and let
$$s$$
represent the price the store sells the merchandise for after the markup.
a.   Write an equation to determine the selling price,
$$s$$
, based on the warehouse purchase price,
$$p$$
.
b.   Create a table showing possible pairs of solutions to the equation.
{"table": [{"_attributes": {"align": "Center", "class": ["table", "table-bordered"], "style": "width:50%"}, "tbody": [{"tr": [{"td": [{"_attributes": {"style": "background-color:#eeeeee; text-align:center"}, "strong": [{"span": [{"_attributes": {"class": ["math-tex"]}, "_value": "$$p$$"}], "_values": ["Warehouse price (", ")"]}]}, {"_attributes": {"style": "background-color:#eeeeee; text-align:center"}, "strong": [{"span": [{"_attributes": {"class": ["math-tex"]}, "_value": "$$s$$"}], "_values": ["Selling price (", ")"]}]}]}, {"td": [{}, {}]}, {"td": [{}, {}]}, {"td": [{}, {}]}, {"td": [{}, {}]}]}]}]}
c.   Create and label a graph for your table.
d.   Interpret the points
$$(0, 0)$$
and
$$(1, r) $$
from the graph in context of the situation.


aligns: yes