For the following exercises, consider a pizzeria that sell pizzas for a revenue of R(x) = ax and costs \(C(x)=b+c x+d x^{2}\) , where x represents the number of pizzas.

Find the profit function for the number of pizzas. How many pizzas gives the largest profit per pizza?

Text Transcription:

C(x)=b+cx+dx^2

March 2125, 2016 Section 3.2 Suppose f’(x) >0 for all x on an open interval I. Suppose x < x i1 I. 2 en f(x) is continuous on [x1 x2] and it is differentiable on (x 1 x 2 2 x ¿ So by Mean Value Theorem there is c ¿ f( )1f ¿ ' ϵ ( 1x S2)hthen f (c)=¿ Which implies Thus f(x)< 0 is increasing on I. By similar arguments, we can show that f’(x)< 0 on an open interval f is decreasing on I. And if f’(x)=0 on an open interval I, then f(x) is constant on I. Theorem If f’(x)= g’(x) on an open interval I, then g(x)= f(x) + c for some constant c. 3 2 Sketch curve y= x 3x + 7x2 Step 1 Find Critical points ' 2 y =3x −6 x+7 2 (−6) −4 3 )7 )<0 No real roots y’ >0 for all real x So y is increasing 3 2 Find the root for y= x 3x + 7x2 Can we estimate the root Since y(0)= 2 y(1)=3 The root is between 0 and I, not a rational root so we use technology to approximate. ‘ ‘ ‘ ‘ ‘ ‘ ‘ ¿3x−2 Domainis −∞,∞ ) y x +1 2 3 (x +1 − (x−2 2 )( ) y’(x)= 2 2 x +1 ) −3x +4x+3