Math Problem Statement
Solution
The equation given is:
Step-by-step solution:
-
Rearrange the equation:
Subtract 2 from both sides to simplify the equation:
This simplifies to:
-
Use the Pythagorean identity:
We know that . Substitute this into the equation:
Simplify the equation:
Multiply the equation by -1 to make the leading coefficient of positive:
-
Solve the quadratic equation:
Now solve for using the quadratic formula. This is a standard quadratic equation in the form:
Factor it:
So, the solutions are:
-
Consider the valid solutions:
- is valid because the cosine function can take the value 1. This happens when , where is any integer.
- is not valid because the cosine function can only take values between -1 and 1.
-
Final solution:
The exact solution is for any integer .
Answer:
The correct choice is .
Would you like more details or have any questions? Here are five related questions to further your understanding:
- How would you solve this equation if the quadratic had no real roots?
- What is the general form of the quadratic formula, and how does it apply here?
- Why is not a valid solution in trigonometry?
- How does the periodic nature of cosine affect the general solution for ?
- Could there be additional solutions if we considered negative angles?
Tip: Always check the domain of trigonometric functions to ensure that all solutions are valid in the context of the equation!
Ask a new question for Free
By Image
Drop file here or Click Here to upload
Math Problem Analysis
Mathematical Concepts
Trigonometry
Quadratic Equations
Trigonometric Identities
Formulas
Pythagorean Identity: sin^2(x) = 1 - cos^2(x)
Quadratic equation: ax^2 + bx + c = 0
Theorems
Pythagorean Identity
Quadratic Factorization
Suitable Grade Level
Grades 9-12