1, when -x<;,-x <; 0 into -x? -2x-3。 have
f(-x)=-(-x)? -2(-x)-3=-x? +2x-3= -(x? -2x+3)=-f(x)∴f(-x)=-f(x);
2. when x
f(-x)=(-x)? -2(-x)+3=x? +2x+3= -( -x? -2x-3)=-f(x) ∴ f(-x)=-f(x)
3 and f(0)=0.
∴ In the domain of f(x), there is f (-x) =-f(x). According to odd function's definition, f (x) is known as odd function. Complete the certificate.