Etienne used a 10-20 placement system for ?
electrodes. In this system, the distance between each
one is either 10% or 20% of the total front-to-back distance
of a person's skull. One patient's skull measures 36 cm.
What's the smallest distance between their electrodes?

answer: 204

step-by-step explanation:

we are told that the revenue is

x⋅(4080−10x)=−10x^2+4080x

this is a quadratic function, so to maximize it we should find the x-value of its vertex. recall that the x-value of the vertex of the parabola ax^2+bx+c is given by the formula −b/2a.

so in this case, we have a=−10 and b=4080, so the x-value of the vertex is

−b/2a= −(4080)/2(−10)=204

doubled

step-by-step explanation: