Trigonometry & Inverse Trigonometry
Inverse Trigonometric Functions
nta_pyq_2025_jan
Grade 11
Question:
cos(sin -1 3 + sin -1 5 + sin -1 33 ) is equal to: 5 13 65
Step-by-Step Solution
Key Concept: Apply the core result for inverse trigonometric equations and simplify using the given constraints.
cos(sin -1 3 + sin -1 5 + sin -1 33 ) 5 13 65 (2) 3 5 33 -1 -1 -1 cos(tan + tan + tan ) 4 12 56 3 5 ⎛ ⎛ + ⎞ 4 12 33 ⎞ -1 -1 cos tan + tan 3 5 ⎝ ⎝ 1 + ⎠ 56 ⎠ ⋅ 4 12 56 56 -1 -1 cos(tan + cot ) 33 33 \pi cos( ) = 0 2
Correct Answer: 2