f(x)=asin(x+pi/4)+bsin(x-pi/4)是偶函数则有序实数对(a,b)可以是

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f(x)=asin(x+pi/4)+bsin(x-pi/4)是偶函数则有序实数对(a,b)可以是

f(x)=asin(x+pi/4)+bsin(x-pi/4)是偶函数则有序实数对(a,b)可以是
f(x)=asin(x+pi/4)+bsin(x-pi/4)是偶函数则有序实数对(a,b)可以是

f(x)=asin(x+pi/4)+bsin(x-pi/4)是偶函数则有序实数对(a,b)可以是
f(x)=asin(x+π/4)-bsin(π/4-x)
=asin(x+π/4)-bcos[π/2-(π/4-x)]
=asin(x+π/4)-bcos(x+π/4)
=√(a^2+b^2)*sin(x+π/4-z)
其中tanz=b/a
是偶函数
所以√(a^2+b^2)*sin(x+π/4-z)=√(a^2+b^2)*sin(-x+π/4-z)
sin(x+π/4-z)=sin(-x+π/4-z)
x+π/4-z=2kπ+(-x+π/4-z)或x+π/4-z=2kπ+π-(-x+π/4-z)
x+π/4-z=2kπ+(-x+π/4-z)
则x=kπ,不是恒成立,所以不和意义
x+π/4-z=2kπ+π-(-x+π/4-z)
x+π/4-z=2kπ+π+x-π/4+z
π/2=2kπ+π+2z
z=-kπ-π/4
所以b/a=tanz-1
b=-a
所以(a,b)可以是(1,-1),或(-5,5)等