few_shots: 
Example:
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.

Now, determine whether the following problem or activity can enable students to understand the concepts or skills in the provided description.

shot_info: fl_problem_001894_pos_0

HS_0
standard_description: Identify shapes as two-dimensional (lying in a plane, “flat”) or three-dimensional (“solid”).
problem_activity: Problem 1
Four sequences are shown below. Which one does not belong and why?
|  $${4, 8, 12, 16, 20 ...}$$  |    $${50, 46, 42, 38, 34, ...}$$    |
|------------------------------|-------------------------------------|
| $${1, 4, 16, 64, 216, ...}$$ | $${1600, 400, 100, 25, 12.5, ...}$$ |
Problem 2
Complete each sequence by filling in the missing terms. Then identify each sequence as arithmetic or geometric and name the common difference or common ratio.
a.
$${-2}$$
,
$$4$$
, ___, ___, ___,
$${28}$$
, ...
b.
$${{1\over2}}$$
, ___, ___,
$$4$$
,
$$8$$
, ___, …
c.
$$5$$
, ___, ___, ___,
$${2{1\over3}}$$
,
$${1{2\over3}}$$
, ...
d.   ___,
$$3$$
,
$${-9}$$
, ___,
$$-81$$
, ___, …
Problem 3
Write a recursive formula for each sequence.
a.
$${11, \space14,\space 17,\space 20,\space 23, …}$$
b.
$${{1\over9},\space {1\over3},\space1,\space 3,\space 9,\space …}$$
c.
$${32,\space 16,\space 8,\space 4,\space 2,\space …}$$


aligns: no