Find the sum of the series using the formula

s=a1/(1-r)

27 + 9 + 3 + 1 +

We have a1 = 27 and r = 3 (because 27:9 = 3; 9:3 = 3; 3:3 = 1);

Then s = 27 / (1 - 3) ;

Finally, s = - 27 / 2;

Step-by-step explanation:

if the eqn of the parabola is f(x) = (x-4)(x+2), we need to mult. this out to find the coordinates of the vertex.

then f(x) = x^2 + 2x - 4x - 8, and f(x) = x^2 - 2x - 8.

one way in which you can find the vertex is to calculate x = -b / (2a).   here, that comes to

        )

x = = 1.   f(1) = 1^2 - 2(1) - 8 = - 9.   vertex is at (1, -9).

        2(1) 

find another point on the curve:   let x=0, for which y=-8.   then (0, -8) is on the curve.   plot the vertex and this point and draw a smooth parabola thru both.

hope this