Thursday

August 28, 2014

August 28, 2014

Posted by **Johnny** on Friday, October 15, 2010 at 9:38am.

- Math ( not J&W) -
**Reiny**, Friday, October 15, 2010 at 9:54amseveral ways to do this.

quickest way:

the x of the vertex is -b/(2a)

= -(-40)/8 = 5

sub back into equation

y = 4(25) -40(5) + 96 = -4

vertex (5,-4)

calculus way:

dy/dx = 8x - 40 = 0

x = 5

proceed as above

completing the square:

y = 4x^2 - 40x + 96

= 4(x^2 - 10x +**25 - 25**+ 96

= 4((x-5)^2 - 25) + 96

= 4(x-5)^2 - 100 + 96

=4(x-5)^2 - 4

**Related Questions**

Math- Algebra 2 - write in vertex form (by completing the square)y=4x2+40x+96

Math- Algebra 2 - write in vertex form (by completing the square)y=4x2+40x+96

Algebra Word Problem Help - A gardener has 40 feet of fencing with which to ...

Algebra Word Problem Help - A gardener has 40 feet of fencing with which to ...

Math - Find the vertex of the parabola. y = -4x2 - 16x - 11

math - Find the vertex of the parabola. y = -4x2 - 16x - 11

math - 1 identify the coordinates of the vertex and the equation of the axis of ...

math - A parabola has the equation y = 4(x-3)^2-7 Choose 2 true statements: A) ...

algebra - Identify the vertex and axis of symetry of the parabola. Identify ...

math - A parabola has the equation y = 4(x-3)^2-7 Choose 2 true statements: A) ...