Question

Given f(t)=t to the power of 4 +t² -5, find the value of f(b) - f(-b)

Answer 1

$f(t)=t^4+t^2-5\\ \\ f(b)-f(-b)=b^4+b^2-5-[(-b)^4+(-b)^2-5]\\ \\ f(b)-f(-b)=b^4+b^2-5-b^4-b^2+5\\ \\ \boxed{f(b)-f(-b)=0}$

Answer 2

$f(b)-f(-b)=b^4+b^2-5-((-b)^4+(-b)^2-5)\\ f(b)-f(-b)=b^4+b^2-5-(b^4+b^2-5)\\ f(b)-f(-b)=b^4+b^2-5-b^4-b^2+5\\ f(b)-f(-b)=0$