if sinA=3/5, in first quadrant, find the values of sin2A,cos2A,tan2A and sin4A. Share with your friends Share 9 Manbar Singh answered this sin A = 35, A lies in first quadrant Hence, cos A = 1 - sin2A = 1 - 925 = 1625 = ±45Since A lies in first quadrant, thencos A = 45Now,i. sin 2A = 2 sin A cos A = 2 × 35 × 45 = 2425ii. cos 2A = 2 cos2A - 1 = 2 452 - 1 = 2 × 1625 - 1 = 3225 - 1 = 32 - 2525 = 725 iii. tan 2A = sin 2Acos 2A = 2425725 = 2425 × 257 = 247iv. sin 4A = sin 2 2A = 2 sin 2A cos 2A = 2 × 2425 × 725 = 336625 6 View Full Answer
