sin2x+cos2x始终如一

景荀军1881化简sin2x+cos2x sin2x+cos2x =根2·【cos45·sin2X+sin45·cos2X】 =根2·sin[2X+45] 根2怎么来的
龙树肺17773587865 ______ sin2x+cos2x =1*sin2x+1*cos2x=(√2/√2)*sin2x+(√2/√2)*cos2x=√2·[(√2/2)*sin2X+(√2/2)*cos2X]=√2·【cos45°·sin2X+sin45°·cos2X】 =√2·sin(2X+45°)就是为了利用cos45°=√2/2=sin45°凑出来的√2.

景荀军1881化简y=sin2x+cos2x -
龙树肺17773587865 ______[答案] y=sin2x+cos2x =√2sin(2x+π/4).

景荀军1881sin2x+cos2x=根号2sin(2x+四分之派)怎么求的 -
龙树肺17773587865 ______[答案] sin2x+cos2x =√2(√2/2·sin2x+√2/2·cos2x) =√2(sin2xcosπ/4+cos2xsinπ/4) =√2sin(2x+π/4)

景荀军1881cos2x + sin2x = ?求解题过程 -
龙树肺17773587865 ______ cos2x+sin2x=sin2x+cos2x=(√2)*[(√2/2)sin2x+(√2/2)cos2x]=√2*[sin2xcos(π/4)+cos2xsin(π/4)]=√2sin(2x+π/4)

景荀军1881sin2x+cos2x=根号2倍(2x+四分之派),为什么?sin2x+cos2x=根号2倍sin(2x+四分之派),为什么?那为什么第一步要先提出一个根号2呢? -
龙树肺17773587865 ______[答案] 由sinπ/4=cosπ/4=根号2/2sin2x+cos2x=根号2(sin2x*根号2/2+cos2x*根号2/2)=根号2*(sin2x*cosπ/4+cos2x*sinπ/4)再由sin(a+b)=sina*cosb+sinb*cosa所以,原式=根号2*(sin(2x+π/4))你的式子好像少了个sin....

景荀军1881y=sin2x+cos2x=√2*sin(2x+45°) -
龙树肺17773587865 ______ sin2x+cos2x=根号2(根号2/2sin2x+根号2/2*cos2x)=根号2(cospai/4sin2x+sinpai/4cos2x)=根号2sin(2x+pai/4) 公式:cosasinb+sinacosb=sin(a+b) 不懂问我

景荀军1881f(x)=sin2x+cos2x化简 要详细过程 -
龙树肺17773587865 ______ 解:直接利用辅助角公式 得√2sin(2x+π/4) 很高兴为您解答,祝你学习进步!不懂可追问!

景荀军1881求sin2x+cos2x的单调区间 -
龙树肺17773587865 ______[答案] 因为根据公式asinx+bcosx=根号a^2+b^2sin(x+θ) ∴sin2x+cos2x=根号2sin(2x+π/4) ∴-π/2+2kπ≤2x+π/4≤π/2+2kπ k∈z ∴-3π/8+kπ≤x≤π/8+kπ k∈z π/2+2kπ≤2x+π/4≤3π/2+2kπ k∈z ∴π/8+kπ≤x≤5π/8+kπ k∈z ∴单调增区间为[-3π/8+kπ,π/8+kπ] k∈z 单调减区间...

景荀军18811+sin2x+cos2x怎么做 -
龙树肺17773587865 ______ 1+sin2x+cos2x=1+2sinxcosx+(cosx)^2-(sinX)^2=(cosx)^2+(sinX)^2+2sinxcosx+(cosx)^2-(sinX)^2 =2(cosx)^2+2sinxcosx=2cosx(cosx+sinx)

景荀军1881cos4x=sin2x+cos2x -
龙树肺17773587865 ______ cos4x=cos²2x-sin²2x=cos2x+sin2x (cos2x+sin2x)(cos2x-sin2x)-(cos2x+sin2x)=0 (cos2x+sin2x)(cos2x-sin2x-1)=0 cos2x+sin2x=0,cos2x-sin2x=1 cos2x+sin2x=0 √2sin(2x+π/4)=0 2x+π/4=kπ x=kπ/2-π/8 cos2x-sin2x=1 sin2x-cos2x=-1 √2sin(2x-π/...