Question

plz solve fast I will give brain mark plz ​

Answer 1

Answer:

9.5

Step-by-step explanation:

Given: sin²5° + sin²10° + sin²15° + ..... + sin²85° + sin² 90°

= (sin² 5 + sin² 85) + (sin² 10 + sin² 80) + ... + (sin² 40 + sin² 50) + .. + (sin²45) + sin² 90

= (sin² 5 + cos² 5) + (sin² 10 + cos² 10) + ... +(sin² 40 + cos² 40) + ... (1/2) + 1

= 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + (1/2) + 1

= 9 + 1/2

= 19/2

= 9.5

Hope it helps!