An office building is built in the shape of a four-sided pyramid. It stands 795 feet
tall and is 139 feet
wide at its base. Imagine that a coordinate plane is placed over a side of the building. In the coordinate plane, each unit represents one foot. Enter an absolute value function whose graph is the V-shaped outline of the sides of the building. Take one corner of the building to be the origin of the coordinate plane and express your answer using improper fractions in simplest form, where needed.

Question

An office building is built in the shape of a four-sided pyramid. It stands 795 feet
tall and is 139 feet
wide at its base. Imagine that a coordinate plane is placed over a side of the building. In the coordinate plane, each unit represents one foot. Enter an absolute value function whose graph is the V-shaped outline of the sides of the building. Take one corner of the building to be the origin of the coordinate plane and express your answer using improper fractions in simplest form, where needed.

markchernioglo · Answer

Here is an example of my question, but I still have no clue...

mathmale · Answer

Sorry to let you down, Mark, but I just don't have the time at the moment.  If it was you who wrote what you have shared in gfd.png, I compliment you for the neatness and detail.

markchernioglo · Answer

Its alright....

markchernioglo · Answer

@agent0smith  ok so I do not understand how in the example I get 81.5

markchernioglo · Answer

how do i get there.

agent0smith · Answer

|dw:1473218210466:dw|
$$\large  y = a\left| x - h \right|+k$$Vertex (given on diagram) is (h, k) so plug it in

Value of a is the slope - find the slope of the upward piece of the line.

markchernioglo · Answer

oh wow!

markchernioglo · Answer

is 139 h? and 795 k?

markchernioglo · Answer

y=a|x−139|+795

agent0smith · Answer

That is why you draw a damn diagram first. Make sense of things.

agent0smith · Answer

No, see the diagram for the vertex.

markchernioglo · Answer

ok so y=a|x−69.5|+795

markchernioglo · Answer

Yea?

agent0smith · Answer

Sure.

markchernioglo · Answer

Oh nice, so now I got to find the a value...

markchernioglo · Answer

May you help me find the slope? My brain is seriously about to explode from all the thought I put in.

markchernioglo · Answer

You say a is the slope right?

agent0smith · Answer

You should know how to find slope. Use the slope formula. You have two points, the origin (0, 0) and the vertex.

agent0smith · Answer

And keep in mind it's an upside down abs. value, so you need to make $ a $ negative

markchernioglo · Answer

ooooh so is it y=a|x−69.5|+795
                      0=a|0−69.5|+795
                      0=a|69.5|+795
                      -795=a|69.5|
                           -795/-69.5

markchernioglo · Answer

agent are my steps correct?

markchernioglo · Answer

agent?

agent0smith · Answer

As i said, you can just find the slope... using the slope formula and the two points i gave.

markchernioglo · Answer

I dont understand

markchernioglo · Answer

Sorry I am bothering you so much

agent0smith · Answer

Use the slope formula to find a. You have two points, the origin (0, 0) and the vertex on my diagram.

Remember a needs to be negative

What you did is probably fine too. You should know how to find slope.. google the slope formula.

mathstudent55 · Answer

|dw:1473230478752:dw|

mathstudent55 · Answer

|dw:1473230795194:dw|

mathstudent55 · Answer

"Imagine that a coordinate plane is placed over a side of the building."

agent0smith · Answer

@mathstudent55 it isn't clear if they intend it to be that way, or the way i interpreted it, with the coordinate plane placed flat onto the side.