Question

cat e suma sin²1grad+sin²2grade+...+sin²90grade?

Answer 1

Salve!

 Folosesti formulele sin(x) = cos(90 grade - x) si $(sin x) ^{2} +(cosx) ^{2} =1;$
De exemplu: sin(1grad)=cos(89grade) =>$(sin1grad) ^{2} =(cos89grade) ^{2} ;$
La rezultat o sa ai 44 de 1 + $(sin45grade) ^{2} +(sin90grade) ^{2}$=>
44+(1/2)+1=>91/2 .

Salutare!