Which statement best describes how to determine whether f(x) = 9 – 4x^2 is an odd function?

Determine whether 9 – 4(–x)2 is equivalent to 9 – 4x2.
Determine whether 9 – 4(–x2) is equivalent to 9 + 4x2.
Determine whether 9 – 4(–x)2 is equivalent to –(9 – 4x2).
Determine whether 9 – 4(–x2) is equivalent to –(9 + 4x2).

Question

Which statement best describes how to determine whether f(x) = 9 – 4x^2 is an odd function?

Determine whether 9 – 4(–x)2 is equivalent to 9 – 4x2.
Determine whether 9 – 4(–x2) is equivalent to 9 + 4x2.
Determine whether 9 – 4(–x)2 is equivalent to –(9 – 4x2).
Determine whether 9 – 4(–x2) is equivalent to –(9 + 4x2).

misty1212 · Answer

HI!!

misty1212 · Answer

a bit confusing because it is certainly not odd !

misty1212 · Answer

oh i see, they want you to say C even though it is silly

misty1212 · Answer

if $f$ is odd, that means 
$$f(-x)=-f(x)$$ which is what C says