What is the principal value of ?
Answer and explanation
Correct answer: A.
- Step 1: The principal value branch for the inverse cosine function is .
- Step 2: Apply the inverse cosine reflection identity: .
- Step 3: Since , subtract: .
Answer
.
Why not the others: The alternative choices (, , ) stem from algebraic sign mistakes, misapplying coordinate formulas, or intermediate arithmetic calculation slips.
Practise more Basic results.
Free questions with an explanation for every one, and full timed CBSE Class 12 mock tests.