Potreste svolgerlo, grazie!
Potreste svolgerlo, grazie!
COS(1/2·ACOS(- 3/5) + 2·ATAN(√15))
pongo:
1/2·ACOS(- 3/5) = α
2·ATAN(√15) = β
quindi:
COS(α + β) = COS(α)·COS(β) - SIN(α)·SIN(β)
COS(α) = √5/5
COS(β) = - 7/8
SIN(α) = √(1 - (√5/5)^2)----> SIN(α) = 2·√5/5
SIN(β) = √(1 - (- 7/8)^2)----> SIN(β) = √15/8
√5/5·(- 7/8) - 2·√5/5·(√15/8) = - 7·√5/40 - √3/4
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$cos\bigg[\dfrac{1}{2}cos^{-1}\bigg(-\dfrac{3}{5}\bigg)+2tan^{-1}\sqrt{15}\bigg] =-0,824324598$.