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請問第二小題怎麼寫

4. 試求下列各值:
(1) sin² 10° + sin 20° + sin 30° + sin 40° + sin 50° +sin'60° + sin² 70°+sin'80° (5)
(2) tan 33° Xtan 57° ° (553)
(1) sin² so = cos³ 40° sin² 60°= cos³30° sik³ 70° = cos 20° sin³80°= cos 10°
sino + cos' = 1
(sin" 10° + cos 10") + (sin '20°+ cos' 20") + (sin '30°+ cos 30") + (sin 40° + cos 40°)
= 1 + 1 + 1 + 1
= 4
(2)

Answer 1

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Lin

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