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: 
Construct a tangent line from a point outside a given circle to the circle.

Answer: 
No. This task does not involve drawing lines that are tangent to circles. The only line that may be drawn is the ray between points P and B.

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_neg_0

HS_2
standard_description: Compute unit rates associated with ratios of fractions, including ratios of lengths, areas and other quantities measured in like or different units. For example, if a person walks 1/2 mile in each 1/4 hour, compute the unit rate as the complex fraction 1/2/1/4 miles per hour, equivalently 2 miles per hour.
problem_activity: Problem 1
Jack mixes yellow and blue paint to make a green paint that he will use to paint his basement. He uses a ratio of 3 pints of yellow paint for every 2 pints of blue paint. Jack pours 18 pints of yellow paint into a bucket.
a.   How many pints of blue paint should Jack add to the bucket?
b.   Jack's friend Kyle wants to help paint. Kyle said he has a green paint that is 9 parts yellow paint to 4 parts blue paint. Is Kyle's paint the same shade green as Jack's? Explain why or why not.
Problem 2
Terrance bikes 3.6 miles to school in 18 minutes. Jacqueline bikes 5.4 miles to school in 30 minutes. Assuming each student rode at a constant speed, who is traveling at a faster speed?
Problem 3
At the corner market, you can buy rice by the pound. The table below shows some weights and their corresponding costs.
| **           Rice (lbs.)          ** | **           Cost ($)          ** |
|--------------------------------------|-----------------------------------|
|                  2                   |                11                 |
|                  10                  |                55                 |
|                  13                  |                 ?                 |
|                  ?                   |                88                 |
a.   How much does 13 pounds of rice cost?
b.   How many pounds of rice can you buy with $88?


aligns: yes