You deposit $1000 into an account that pays interest at a 5.5% annual rate compounded continuously. After t years, the balance A in your account is given by the equation A = 10000.055How long will it
take for the balance to grow to $2000? Round your answer to the nearest tenth.

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