Question

cos square 30 degree + sin square 60 degree + sin square 90 degree + cos square 180 degree is equal to 7 bracket sin square 45 + cos square 90 degree close the bracket
Both the side should be same​

Answer 1

Answer:

To prove :-

    cos²30° + sin²60° + sin²90° + cos²180° = 7 (sin²45° + cos²90°)

L.H.S. = cos²30° + sin²60° + sin²90° + cos²180°

          = (√3/2)² + (√3/2)² + (1)² + (-1)²

          = 3/4 + 3/4 + 1 + 1

L.C.M. = 4

⇒ L.H.S. = (3+3+4+4)/4

              = 14/4

              = 7/2

R.H.S. = 7 (sin²45° + cos²90°)

          = 7 ( (1/√2)² + (0)² )

          = 7 × 1/2

          = 7/2

∴ L.H.S. = R.H.S.