let in 相關
廣告
昨晚的回答不知何故又被隱了, 簡單回答吧. 令 x = cos(3π/5) 則 cos(9π/5) = 4x^3 - 3x cos(6π/5) = 2x^2 - 1 cos(9π/5) + cos(6π/5) = 0 即 4x^3 + 2x^2 - 3x - 1 = (x+1)(4x^2 - 2x - 1 ) = 0. 因 π/2 < 3π/5 < π, 故 0 > cos(3π/5) > -1 故 cos(3π/5) = (1-√5)/4.
...2(π - 1) cm³ D. (π - 2) cm³ Solution： Let r be the radius of a identical circle. In the picture 1, A perimeter of an identical circle = the perimeter of the shaded...
...4 = 41 Therefore, P(black) = 41/48. (c) Let the required number be n. After...black balls, there are (48 - n) balls in total where (41 - n) are black. Therefore...
(a) Let height of a larger cylinder = H base area of a larger... As the 2 larger cylinders are recast in 20 smaller cylinders, 2πR²H = 120πr²...
Frist I let the length be l, height be h, and the width be w. Then there will... the basic way to calculate) For more information, just search in Wikipedia and you will get the answer (also Google ...
... paper II) + P(Fail in paper I) P(Pass paper II) ...9) (1 - 2/3) (2/3) + (1 - 7/9) (2/3) (7/9) = 70/243 (bi) Let A be the event A that Julia ...
Question： In ΔACD, AC = AD. B and ... = BC = 40 ...... ( opp. sides of // gram. ) Let G be the mid-pt of DF. ∵ ΔEFG...
let in 相關
廣告
