(a) A pentagon ABCDE has sides AE and CD parallel and the line EC is parallel to side AB. Sides ED and BC, when extended, meet at a
point F. ZABC is equal to ZCDE. Show that ZAEC = ZCFD.
(b) If, furthermore, triangles EDC and DFC are both isosceles, with
ED = DC and DF = FC, find the angles of the pentagon.

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

irrational, then, just means all the numbers that aren't rational. every integer is a rational number, since each integer n can be written in the form n/1. however, numbers like 1/2, 45454737/2424242, and -3/7 are also rational, since they are fractions whose numerator and denominator are integers.

step-by-step explanation: