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, 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
standard_description: Recognize that sequences are functions, sometimes defined recursively, whose domain is a subset of the integers. For example, the Fibonacci sequence is defined recursively by f(0) = f(1) = 1, f(n+1) = f(n) + f(n-1) for n ³ 1.
problem_activity: Problem 1
Consider the sequence below.
$${1, \space1,\space 2,\space 3,\space 5,\space 8,\space 13,\space 21, \space34, …}$$
a.   Describe the pattern that you notice. How is each next term determined?
b.   This pattern is famously called the Fibonacci sequence. Write a recursive formula to represent the Fibonacci sequence. Write a formula in sequence notation using
$${a_n}$$
and in formula notation using
$${f(n)}$$
.
c.   If
$${a_{15}=610}$$
and
$${a_{16}=987}$$
, what are the values of
$${a_{17}}$$
and
$${a_{14}}$$
?
Problem 2
For each sequence below, write a recursive formula, in both sequence notation and function notation, to represent the sequence.
a.
$${18,\space 13,\space 8,\space 3,\space -2,\space …}$$
b.
$${4,\space 12,\space 36,\space 108,\space 324,\space …}$$
Problem 3
A sequence is given by an explicit formula, as shown below, where
$$n$$
represents the term number.
$$a_n=4n-1$$
for
$$n\geq1$$
a.   Write the first five terms in the sequence.
b.   Write a recursive formula to represent the sequence.


aligns: yes