few_shots: 
Example 1:
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.

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


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).

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

Example 3:
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 $P$.


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.

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: Know that straight lines are widely used to model relationships between two quantitative variables. For scatter plots that suggest a linear association, informally fit a straight line, and informally assess the model fit by judging the closeness of the data points to the line.
problem_activity: Problem 1
For the four scatter plots, answer the following questions:
Does there appear to be a relationship between
$$x$$
and
$$y$$
?
If there is a relationship, does it appear to be linear?
If the relationship appears to be linear, is it a positive or negative linear relationship?
If applicable, circle the correct words in this sentence: There is a (positive/negative) association between
$$x$$
and
$$y$$
because as
$$x$$
increases, then
$$y$$
tends to (increase/decrease).
a.
[IMG]
b.
[IMG]
c.
[IMG]
d.
[IMG]
Problem 2
Pablo is curious if there is a relationship between the amount of time high school students spend on social media and their academic achievement. To explore this, he conducts a survey of 30 randomly selected students from his school, and asks them how many minutes they spent on social media yesterday and what their most recent grade point average (GPA) was. Pablo summarized his data in the scatter plot below.
[IMG]
a.   Describe the relationship between the amount of time spent on social media and GPA.
b.   Are there any deviations from the pattern? Explain what you see.
c.   Are there any clusters of data? What do they mean in context?


aligns: no