The value of cos ⁡ 2 π 63 cos ⁡ 3 π 70 cos ⁡ 4 π 77 cos ⁡ π 72 cos ⁡ π 40 cos ⁡ 3 π 88 1 cos ⁡ π 90 cos ⁡ 2 π 99 is equal to

Step-by-step solution

The given determinant = cos ⁡ π 7 - π 9 cos ⁡ π 7 - π 10 cos ⁡ π 7 - π 11 cos ⁡ π 8 - π 9   cos ⁡ π 8 - π 10   cos ⁡ π 8 - π 11 cos ⁡ π 9 - π 9 cos ⁡ π 9 - π 10 cos ⁡ π 9 - π 11 = cos ⁡ π 7 cos ⁡ π 9 + sin ⁡ π 7 sin ⁡ π 9   cos ⁡ π 7 cos ⁡ π 10 + sin ⁡ π 7 sin ⁡ π 10 &#160