Evaluate cos^2 0°+cos^2 1°+........ +cos^2 88°+cos^2 89°
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what do u mean by "......."
you should have atleast completed the question
you should have atleast completed the question
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cos^2 0°+cos^2 1° + cos^2 2°+........+ cos^2 88° + cos^2 89°
=cos^2 0° + cos^2 1° +......+
cos^2 (90°- 2°) + cos^2 (90°-1°)
=cos^2 0° + cos^2 1° + cos^2 2°+........+ sin^2 2° + sin^2 1° 【cos(90°-x)=sinx】
=cos^2 0°+ cos^2 1° +...+ cos^2 44° + cos^2 45° + sin^2 44 + sin^2 43° + .....+ sin^2 2° + sin^2 1°
= cos^2 0° + 44 + cos^2 45°
【 sin^2 x +cos^2 x =1 】
= 1 +44+ (1/√2)^2
=45+1/4
=181/4
=cos^2 0° + cos^2 1° +......+
cos^2 (90°- 2°) + cos^2 (90°-1°)
=cos^2 0° + cos^2 1° + cos^2 2°+........+ sin^2 2° + sin^2 1° 【cos(90°-x)=sinx】
=cos^2 0°+ cos^2 1° +...+ cos^2 44° + cos^2 45° + sin^2 44 + sin^2 43° + .....+ sin^2 2° + sin^2 1°
= cos^2 0° + 44 + cos^2 45°
【 sin^2 x +cos^2 x =1 】
= 1 +44+ (1/√2)^2
=45+1/4
=181/4
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