What is the missing reason for the 5th step in the proof below A. Simplification of equation from previous step B. Definition of complementary angles C. Substitution D. Definition of a linear pair

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

other answer is correct. i had used the radius of the radius somehow. a website:

c. 6tan80

step-by-step explanation: