Question

A small company that manufactures snowboards uses the relation below to model its profit. In the model,

represents the number of snowboards in thousands, and P represents the profit in ten thousands of dollars.
What is the maximum profit the company can earn? How many snowboards must it produce to earn this
maximum profit?
a. Factor P =
4x2 + 32x + 336 to find the roots.
b. Find the axis of symmetry then use it to find the vertex.
c. Therefore, we need to see snowboards to make a maximum profit of

Answer 1

a) x₁ = 14

x₂ = - 6

b) x = 4

c) P(max ) = 4000000 $

Explanation:

To find the axis of symmetry we solve the equation

a) -4x² + 32x + 336 = 0

4x² - 32x - 336 = 0 or x² - 8x - 84 = 0

x₁,₂ = [ -b ± √b² -4ac ]/2a

x₁,₂ = [ 8 ±√(64) + 336 ]/2

x₁,₂ = [ 8 ± √400 ]/2

x₁,₂ =( 8 ± 20 )/2

x₁ = 14

x₂ = -6

a) Axis of symmetry must go through the middle point between the roots

x = 4 is the axis of symmetry

c) P = -4x² + 32x + 336

Taking derivatives on both sides of the equation we get

P´(x) = - 8x + 32 ⇒ P´(x) = 0 - 8x + 32

x = 32/8

x = 4 Company has to sell 4 ( 4000 snowboard)

to get a profit :

P = - 4*(4)² + 32*(4) + 336

P(max) = -64 + 128 + 336

P(max) = 400 or 400* 10000 = 4000000