few_shots: Example:
Problem/activity:
Find the general solution for:
$${\mathrm{cos}\left({\pi\over2}+x\right)=\mathrm{tan}{\pi\over4}}$$


Mathematical concept/skill options: 
A. Prove and apply trigonometric identities.
B. Model periodic phenomena with trigonometric functions.
C. Interpret functions that arise in applications in terms of the context.
D. Build a function that models a relationship between two quantities.
E. Define, evaluate, and compare functions.
F. Use functions to model relationships between quantities.
G. Understand the concept of a function and use function notation.
H. Analyze functions using different representations.
I. Extend the domain of trigonometric functions using the unit circle.
J. Interpret expressions for functions in terms of the situation they model.
K. Build new functions from existing functions.
L. Construct and compare linear and exponential models and solve problems.


Your response, in json format:
{
  "explanation": "This problem applies trigonometric identities, including the angle addition formula for cosine.",
  "answer": "A"
}

Now, assign the following problem or activity to one or more relevant mathematical concepts/skills it teaches.
shot_info: fl_problem_001894

HS
options: Rewrite rational expressions.

Perform arithmetic operations on polynomials.

Represent and analyze quantitative relationships between dependent and independent variables.

Analyze and solve linear equations and pairs of simultaneous linear equations.

Interpret the structure of expressions.

Understand properties of multiplication and the relationship between multiplication and division.

Gain familiarity with factors and multiples.

Write expressions in equivalent forms to solve problems.

Understand solving equations as a process of reasoning and explain the reasoning.

Multiply and divide within 100.

Create equations that describe numbers or relationships

Add and subtract within 20.

Solve equations and inequalities in one variable.

Represent and solve problems involving addition and subtraction.

Understand and apply properties of operations and the relationship between addition and subtraction.

Write and interpret numerical expressions.

Analyze patterns and relationships.

Represent and solve equations and inequalities graphically.

Solve problems involving the four operations, and identify and explain patterns in arithmetic.

Work with radicals and integer exponents.

Use polynomial identities to solve problems.

Represent and solve problems involving multiplication and division.

Understand the relationship between zeros and factors of polynomials.

Generate and analyze patterns.

Solve real-life and mathematical problems using numerical and algebraic expressions and equations.

Use properties of operations to generate equivalent expressions.

Understand addition as putting together and adding to, and understand subtraction as taking apart and taking from.

Solve systems of equations.

Understand the connections between proportional relationships, lines, and linear equations.

Work with equal groups of objects to gain foundations for multiplication.

Work with addition and subtraction equations.

Apply and extend previous understandings of arithmetic to algebraic expressions.

Use the four operations with whole numbers to solve problems.

Reason about and solve one-variable equations and inequalities.
problem_activity: Task
Anna and Jason have summer jobs stuffing envelopes for two different companies. Anna earns \$14 for every 400 envelops she finishes. Jason earns \$9 for every 300 envelopes he finishes.
Draw graphs and write equations that show the earnings, $y$ as functions of the number of envelopes stuffed, $n$ for Anna and Jason.
Who makes more from stuffing the same number of envelopes? How can you tell this from the graph?
Suppose Anna has savings of \$100 at the beginning of the summer and she saves all her earnings from her job. Graph her savings as a function of the number of envelopes she stuffed, $n$. How does this graph compare to her previous earnings graph? What is the meaning of the slope in each case?


correct_option_index: 28