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find the value of sin ²5+sin²10+......................................+sin²90

find the value of  sin²5+sin²10+......................................+sin²90
 

Grade:11

1 Answers

Aarya bora
11 Points
4 years ago
Sin25+ Sin285=sin25+ cos25=1.  Similarly bro we can form pairs of 10 &80 , 15&75 20&70...25&65....30&60.....35&55....40&50....       and sin245 is ½   And sin290 is 1      So therefore 8 pairs of sin+ cos2. Therefore  8 times 1 is 8 + ½ +1/2=9+ ½
 

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