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: 
Solve quadratic equations in one variable.

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


Answer: 
Yes. This task shows one quadratic equation with one variable, x.

Example 3:
Concept/skill: 
Construct a tangent line from a point outside a given circle to the circle.

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: 
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: Recognize that in a multi-digit number, a digit in one place represents 10 times as much as it represents in the place to its right and 1/10 of what it represents in the place to its left.
problem_activity: Problem 1
a.   Solve.
$$0.03 \times 10$$
= ___________
$$0.106 \times 10$$
= ___________
$$54.8 \times 10$$
= ___________
b.   What do you notice about Part (a)? What do you wonder?
Problem 2
a.   Solve.
$$0.09 \times 10 =$$
___________
$$0.09 \times 100=$$
___________
$$0.09 \times 1,000= $$
___________
b.   What do you notice about Part (a)? What do you wonder?
c.   Solve.
$$70.6 \times 10=$$
___________
$$70.6 \times 10^2 =$$
___________
$$70.6 \times 10^3 =$$
___________
d.    What do you notice about Part (c)? What do you wonder?
e.   Use your conclusions from Parts (b) and (d) to find the solutions below.
$$23.48 \times 10,000 =$$
___________
$$6.059 \times 10^3 =$$
___________
Problem 3
The value of the 8 in 83.16 is how many times the value of the 8 in 7.8?


aligns: yes