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: 
Solve quadratic equations in one variable.

Answer: 
Yes. This task shows one quadratic equation with 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_pos_0

HS_1

im_task_001160_neg_0

HS_2
standard_description: Determine the unknown whole number in a multiplication or division equation relating three whole numbers. For example, determine the unknown number that makes the equation true in each of the equations 8 × ? = 48, 5 = �� ÷ 3, 6 × 6 = ?.
problem_activity: Narrative
The purpose of this activity is for students to build and compare flat and solid shapes. Students are not expected to build precise shapes. Using clay to build the shapes helps students feel the difference between flat and solid shapes. The terms “flat” and “solid” are introduced in the activity synthesis. Students may benefit from getting to hold and see the solid shapes up close as they build them.
Required Materials
Materials to Gather
Clay
Required Preparation
Each student needs a piece of clay.
Gather a cone and cylinder to display.
Launch
Groups of 2
Give each student a piece of clay.
“Use your clay to make a shape that you know.”
1 minute: independent work time
“Share your shape with your partner. How are they the same? How are they different?” (The shapes are different. I made a circle and my partner made a triangle.)
30 seconds: quiet think time
1 minute: partner discussion
Share responses.
Activity
Display a cylinder.
“Make this shape with your clay.”
2 minutes: independent work time
Display a cone.
“Make this shape with your clay.”
2 minutes: independent work time
“Describe the shape that you made to your partner. What does it look like?” (It looks like an ice cream cone. It’s tall. It has a point on the bottom.)
30 seconds: quiet think time
2 minutes: partner discussion
Share responses.
Student Response
Teachers with a valid work email address can
click here to register or sign in
for free access to Student Response.
Activity Synthesis
Display a group of flat shapes and a group of solid shapes that students created.
“What is different about the shapes that we made first and the rest of the shapes that we made?” (The shapes that we made first are all flat. The other shapes stick up.)
“The first shapes that we made were flat shapes, like circles and rectangles. Then we built some other shapes. What can we call these shapes?” (solid shapes, big shapes)
“These shapes are solid shapes.”
“Use your clay to make a flat shape.”
“Use your clay to make a solid shape.”


aligns: no