To solve the equation , we will use trigonometric reduction formulas (reduction identities). 1. Applying Reduction Formulas First, let's simplify each term using standard trigonometric identities:
- For the first term:
Since is an "odd" multiple of , the function changes from cosine to sine. In the second quadrant, cosine is negative.
For the second term:
Since is an "even" multiple of , the function remains sine. In the second quadrant, sine is positive.
2. Substituting back into the Equation Now, substitute these simplified terms back into the original equation: Combine the like terms: 3. Solving for x Divide both sides by : The general solution for the equation is found at the points where the sine function crosses the horizontal axis on the unit circle ( ): Final Answer: Would you like me to check if specific solutions fall within a particular numerical interval?