Question:
If sin A = 3/5 and cos B = 4/5, and both A, B are in first quadrant, then sin(A + B) = ?
यदि sin A = 3/5 और cos B = 4/5, और दोनों A, B प्रथम चतुर्थांश में हैं, तो sin(A + B) = ?
Options:
- a) 12/25
- b) 7/10
- c) 24/25
- d) 4/5
- a) 12/25
- b) 7/10
- c) 24/25
- d) 4/5
correct answer : c)
Explanation:
cos A = 4/5, sin B = 3/5. sin(A+B) = sinA cosB + cosA sinB = (3/5)(4/5) + (4/5)(3/5) = 24/25.
cos A = 4/5, sin B = 3/5. sin(A+B) = sinA cosB + cosA sinB = (3/5)(4/5) + (4/5)(3/5) = 24/25.