arccos(sin((5pi)/2))

解答

arccos (sin (\frac{5 π}{2}))

0

求解步骤

arccos (sin (\frac{5 π}{2}))

使用三角恒等式改写:

sin (\frac{5 π}{2}) = cos (- 2 π)

sin (\frac{5 π}{2})

cos (\frac{π}{2} - x) = sin (x)

= cos (\frac{π}{2} - \frac{5 π}{2})

= cos (- 2 π)

= arccos (cos (- 2 π))

Use the inverse trig property:

0

arccos (cos (- 2 π))

对于

0 \leq x \leq π, a rccos (cos (x)) = x

使用三角恒等式改写:

cos (- 2 π) = cos (0)

cos (- 2 π)

cos (x + 2 π \cdot k) = cos (x)

= cos (- 2 π + 1 \cdot 2 π)

= cos (0)

= arccos (cos (0))

0 \leq 0 \leq π

= 0

= 0

sin (\frac{7 π}{8}) - sin (\frac{7 π}{6}) - cot (\frac{π}{3})

2 sin (6 0^{\circ}) sec (3 0^{\circ}) cos (4 5^{\circ}) tan (4 5^{\circ})

cos (3 0^{\circ}) + tan (4 5^{\circ})

arctan (\frac{2.5}{1.8})

7 sin (4 0^{\circ})