consider the quadratic function f(x)=2x^2 - 8x - 5 ..the smallest zero of the function is??? and how to find?? thanks!

Question

anonymous · Answer

+ last year, a music theatre charged 60$ admission and at that price an average of 200 seats were sold for each show. a survey predicts that for every $5 increase in ticket price, ten fewer people would be expected to attend a show.. write the quadratic function to model this equation. determine the admission price that would maxinmize revenue and how many seats would be empty when revenue is maximized compared to last year's average?

please help!

campbell_st · Answer

you  can either complete the square of use the general quadratic formula

my choice is GQF...

anonymous · Answer

how..? is this for the first question?

anonymous · Answer

the answer is -.55 but i dont know how to get it

anonymous · Answer

$$2x^{2}-8x-5$$
a=2
b=-8
c=-5

Input those into the quadratic equation.

campbell_st · Answer

using my CAS calculator I got

$$x= \frac{\sqrt{26} -4}{2}$$

campbell_st · Answer

thats the smaller value the larger is 

$$x = \frac{\sqrt{26} +4}{2}$$

anonymous · Answer

first one should be 4 - the root, not the other way around.