arccos(θ)=1.6

解答

arccos (θ) = 1.6

θ = cos (\frac{8}{5})

求解步骤

arccos (θ) = 1.6

使用反三角函数性质

arccos (θ) = 1.6

arccos (x) = a \Rightarrow x = cos (a)

θ = cos (1.6)

cos (1.6) = cos (\frac{8}{5})

cos (1.6)

θ = cos (\frac{8}{5})

θ = cos (\frac{8}{5})

sin (9 0^{\circ} - θ) = 0.5745

sin (x) = \frac{60}{61}

so l v e f or a, tan (a) = 3

2 cos (12 x) = 3

7 sin (5 x) = 2