How to find polynomial roots on a TI-83 or TI-84 Plus without PolySmlt?

[moonman239]

I'd like to know how to find the root of a polynomial on my TI-84 Plus without this "Polynomial Root Finder and Simultaneous Equation Solver" app. The reason is that the app's not in my calculator and I can't transfer the app to my calculator. I keep getting an "Access Denied" error message and it seems that my calculator has a mind of its own because I hear the dinging and the donging my computer makes whenever a USB device connects or disconnects.

Maybe I'll see if I can get the app from my friend Luke when school starts.

Anyways, is there any way to find the roots of a polynomial without the app?

 

[Millennial]

I think it is fair to say that it depends on the polynomial. For a degree less than five, there is a formula that yields the roots (it is, though, extremely long.) For degrees greater than or equal to five, there is no absolute formula (as shown by Abel and Galois), but specific cases can be handled.

Also, I think Wolfram:Alpha can generate the roots. Google it. It is a website.

 

[moonman239]

I think it is fair to say that it depends on the polynomial. For a degree less than five, there is a formula that yields the roots (it is, though, extremely long.) For degrees greater than or equal to five, there is no absolute formula (as shown by Abel and Galois), but specific cases can be handled.

Also, I think Wolfram:Alpha can generate the roots. Google it. It is a website.

Thanks. Yes, I know about Wolfram:Alpha.
I wonder why something so basic wasn't baked into the OS. They could have put it into the Equation Solver.

 

[moonman239]

I guess I could write a program that would just try values of x and note which x values cause y to approximately equal 0. I would want to figure out how many zeroes there are.

 

[CellCoree]

There are a few ways to find polynomial roots on a TI-83 or TI-84 Plus without using the PolySmlt app. One method is to use the calculator's built-in function, "zero," which can be accessed by pressing the "2nd" button followed by the "calc" button. This function allows you to find the x-intercepts of a graph, which correspond to the roots of a polynomial. However, this method may not be as accurate as using the PolySmlt app.

Another option is to use the calculator's "solve" function, which can be accessed by pressing the "math" button followed by the "0" button. This function allows you to solve equations for a specific variable, so you can input your polynomial as an equation and solve for the variable x to find the roots.

You can also use the calculator's "graph" function to graph the polynomial and visually determine the roots by looking for the points where the graph crosses the x-axis.

It is also possible to manually calculate the roots of a polynomial using the quadratic formula or other methods, but this may be more time-consuming and prone to errors.

In terms of the "Access Denied" error message you are receiving, it is possible that your calculator's operating system needs to be updated or that there is an issue with your USB connection. You may want to try troubleshooting these issues before attempting to transfer the app from your friend's calculator.