If f(x)=ax7+bx3+cx−5,a,b,c are real constants, and f(−7)=7, then the range of f(7)+17cosx is
[−34,0]
[0,34]
[-34,34]
None of these
f(7)+f(−7)=−10
f(7)=−17
or f(7)+17cosx=−17+17cosx
which has the range [-34, 0].