## College Algebra (6th Edition)

We know that if a function is odd, then $f(-x)=-f(x).$ We know that if a function is even, then $f(-x)=f(x).$ Hence we plug in $-x$ to see what happens. $f(-x)=(-x)^4-2(-x)^2+1=x^4-2x^2+1=f(x).$ Therefore the function is even, thus it is symmetric to the y-axis.