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Rolandoland12
a fost răspuns

a.) tg pi_8=√2-1
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Răspuns :

OiLoveYouO
π/2 = 90° ⇒ π/4 = 45° ⇒  π/8 = 45°/2 = 22°30'


Avem formula:

tg (x/2) = sinx / cosx+1

tg (45°/2) = sin45° / (cos45° + 1)

tg (22°30') = √2/2 / 1+(√2/2) 

tg (22°30') =  √2/2 / (2+√2)/2

tg (22°30') = √2/2 × 2/(2+√2)

tg (22°30') = √2 / (2+√2)

tg (22°30') = √2 / √2(√2+1)

tg (22°30') = 1 / √2+1

tg (22°30') = √2-1 / 2-1

tg (22°30') = √2-1

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