Answer: π.
- A π
- B 3π/4
- C π/2
- D 5π/4
Correct answer: A. π
Explanation: tan⁻¹1=π/4. For tan⁻¹2+tan⁻¹3: since xy=6>1 and both positive, formula gives π+tan⁻¹((2+3)/(1−6))=π+tan⁻¹(−1)=π−π/4=3π/4. Total: π/4+3π/4=π. Answer: π.
Unit circle with standard angles 0, 30, 45, 60, 90 degrees; at 45 degrees the point is (cos45, sin45) = (1/sqrt2, 1/sqrt2).
Concept context
Ratios, identities, and applications in triangles