I don't know, I kind of wonder the same thing sometimes. But everyone understands things at a different rate, so that's why I'm here helping people by answering their questions and doing my best to explain how I got there.
<h2><u>Answer:</u></h2><h2>Polynomials have the domain of all Reals. Plugging any Real number into the equation will give you a value. </h2><h2>Domain = {x|x∈R}</h2><h2><u></u></h2><h2><u> Step-by-step explanation:</u></h2><h2>The range is dependent on the curve itself. The axis of symmetry for this function is</h2><h2>x = -b/2a = -1(-10)/2(1) = 10/2 = 5 </h2><h2>The vertex is F(5) = (5)2 + (-10)(5) + 21 = 21 -50 + 21 = -8</h2><h2>Since the leading coefficient is positive, the parabola opens up and the vertex (5,-8) is a local minimum. It turns out to be an absolute minimum too so the Range = {x|x∈R, x≥-8}</h2><h2><u>Thank you</u></h2><h2><u>sunshinemadison101</u></h2>
