Asquare painting canvas has sides of length 45cm. a painter masks off a rectangular area on the canvas. she uses 90cm of tape to mask 3 sides of the rectangle and the 4th side is formed by 1 edge of the canvas. the area enclosed in the rectangle is 1000cm^2. work out the length of the shorter sides of the rectangle.

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