cos5 - cos3

cos5π的三角函数值，带过程！

网友解答：cos5π=cos(4π+π)【=cos(2kπ+π)=cosπ, k=2.】 =cosπ. =-1.

cos5π/3

网友解答：第1个问题: 诱导公式是:sin(α+2πK) 因为sin5π/3＝sin(5π/3+2πK) 因为5π/3=300° 2π=360° 所以sin(300+ -360°)'这里K取-1 =sin(-60°) =sin[- (√3) /2] sin5π/3≠sinπ/3,sinπ/3漏了个负号 第2个问题 2πK+α=sin5π/3 K取-1 -2π+α=sin5π/3 α=sin5π/3+2π...

cos5π/6这类题是怎么算得

网友解答：运用诱导公式规律 奇变偶不变，符号看象限 cos5π/6 ＝cos(π/2+π/3) ＝-sinπ/3 ＝-√3/2

COS5π/3=要步骤

网友解答：cos5π/3=cos(2π-π/3)=cos(-π/3)=cosπ/3=1/2

cos5π/6等于多少的步骤

网友解答：解三角形,y=√3/2,x=1/2 cos5/6π=-√3/2

cos5π/12的值

网友解答：cos5π/12 =cos(π/2-π/12) =sinπ/12 cosπ/6=1-2sin²π/12 cosπ/6=1-2sin²π/12 √3/2=1-2sin²π/12 2sin²π/12=1-√3/2 sin²π/12=1/2-√3/4 sin²π/12=(2-√3)/4 sin²π/12=4(2-√3)/16 sin²π/12=2(4-2√3)/16 sin#...

cos5π等于 =

网友解答：cos5π=cos(2*2π+π)=cosπ=-1 诱导公式

cos5π/2

网友解答：因为2π是最小正周期，所以 cos5π/2=cosπ/2=0

cosπ/12cos5π/12等于多少（过程）

网友解答：cosπ/12cos5π/12 =cos（π/2-5π/12）cos5π/12 =(cosπ/2cos5π/12+sinπ/2sin5π/12)cos5π/12 =sin5π/12cos5π/12 =1/2sin5π/6 =1/4

cos -5π

网友解答：cos（-5π）=cos（-3π）=cos（-π）=-1