The price of a stock, A(x), over a 12-month period decreased and then increased according to the equation... ?

The price of a stock, A(x), over a 12-month period decreased and then increased according to the equation, A(x)=#0.75x^2−6x+20# , where x equals the number of months. The price of another stock, B(x), increased according to the equation B(x)= 2.75x+1.50 over the same 12-month period. Graph and label both equations on the accompanying grid. State all prices, to the nearest dollar, when both stock values were the same.

1 Answer
Jul 29, 2018

Answer:

The stock values are the same for #=$9# and #=30$#

Explanation:

Plot the graph of

#A(x)=0.75x^2-6x+20#

graph{0.75x^2-6x+20 [-10.33, 40.98, -3.18, 22.5]}

Then plot

#B(x)=2.75x+1.50#

graph{2.75x+1.50 [-13.7, 51.24, -0.84, 31.67]}

Then,

plot the graphs on the same plot

graph{(y-0.75x^2+6x-20)(y-2.75x-1.50)=0 [-6.92, 33.61, 6.85, 27.16]}

The points of intersections are

#C=(2.774,9.128)#

and

#D=(8.893,29.956)#