Math, asked by talagapuharikrishna2, 10 months ago

The value of cos square 1 + cos squared 2 + cos square 3 and so on up to cos square 90

Answers

Answered by amitnrw
8

Cos²1°  + Cos²2°  + Cos²3°+.................................+ Cos²89° + Cos²90° = 44.5

Step-by-step explanation:

Cos²1°  + Cos²2°  + Cos²3° +.......................................+ Cos²89° + Cos²90°

= Cos²1°  + Cos²2°  + Cos²3° + .......+  Cos²44° + Cos²45° + Cos²46° +.............+ Cos²89° + Cos²90°

now using Cosα = Sin(90 - α)

Cos²46°  = Sin²44°

Cos²89° = Sin²1°

Cos²88° = Sin²2°

= Cos²1°  + Cos²2°  + Cos²3° + .......+  Cos²44° + Cos²45° +Sin²44° +.............+ Sin²1° + Sin²0°

Sin0° = 0

=  Cos²1°  + Cos²2°  + Cos²3° + .......+  Cos²44° + Cos²45° +Sin²46° +.............+ Sin²1°

= (Cos²1° + Sin²1° ) + (Cos²2° + Sin²2° ) +..............................+ (Cos²44° + Sin²44° )  +  Cos²45°

Cos²α + Sin²α = 1

= 1   + 1  +                                   + 44(times) + Cos²45°

Cos²45° = 1/2

= 44 + 1/2

= 44.5

Cos²1°  + Cos²2°  + Cos²3° +.............................+ Cos²89° + Cos²90° = 44.5

Learn more:

1/cos0.cos1 + 1/cos1.cos2 +1/cos2.cos3 +.....+1/cos88.cos89

https://brainly.in/question/9022549

sin theta/1-cos theta + tan theta / 1+cos theta = sec theta.cosec theta ...

https://brainly.in/question/2089848

Answered by jatothusai154
0

Answer:

44.5

Step-by-step explanation:

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