ldcf.net
ǰλãҳ >> ΪʲôCos(%x)=Cosx >>

ΪʲôCos(%x)=Cosx

ȻλԲ cosֵļ

Ϊy=cosxż cos(-x)cosx

Ϊڵ1͵4cosǵķŶһġ

һλ԰ ǣһxһ-x Կcosx=OA/R //: ҺĶ cos(-x)=OA/R ˣ cos(-x) = cosx ͼ

cosxż

¥cos[cos(cosx)]sin[cos(cosx)]Ǵģ Ҫ֤һ󣬽ٳһɡ žһ x=1()ʱУ cosx=cos10.54030231 cos(cosx)=cos(cos1)0.85755322 sin[cos(cosx)]=sin[cos(cos1)]0.756243...

cosx*(2(cosx)^2-1)=2(cosx)^3-cosx

Ϻ󵼡

Ϊcos(x+h)-cosx=-2sin(x+h/2)sin(h/2) :lim [cos(x+h)-cosx]/h =lim[-2sin(x+h/2)sin(h/2)/h] =lim[-sin(x+h/2)sin(h/2)/(h/2)] =lim[-sin(x+h/2)] =-sinx

⣺ cos2x=cos(x+x) =cosx*cosx-sinx*sinx =(cosx)^2-(sinx)^2 ʽӦõcos(x+y)=cosx*cosy-sinx*sinyx=y

վҳ | վͼ
All rights reserved Powered by www.ldcf.net
copyright ©right 2010-2021
磬ַϵͷzhit325@qq.com