若f(x)=asin(x+π/4)+bcos(x-π/4) (ab不等于0是偶函数,则有序数对(a,b)可以是————(其中一对

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若f(x)=asin(x+π/4)+bcos(x-π/4) (ab不等于0是偶函数,则有序数对(a,b)可以是————(其中一对
若f(x)=asin(x+π/4)+bcos(x-π/4) (ab不等于0是偶函数,则有序数对(a,b)可以是————(其中一对

若f(x)=asin(x+π/4)+bcos(x-π/4) (ab不等于0是偶函数,则有序数对(a,b)可以是————(其中一对
f(x)=asin(x+π/4)+bcos(x-π/4)
=asin(x+π/4)+bsin(π/2+x-π/4)
=asin(x+π/4)+bsin(x+π/4)
=(a+b)sin(x+π/4),
由于sin(x+π/4)不是偶函数,
要使得f(x)为偶函数,需有a+b=0,
所以满足此条件的都可以,当然ab≠0.
比如a=1,b=-1或a=-1,b=1等等...