When is a graphing calculator preferable to finding the solutions to an equation?

Well, try to find the solution for this…

-0.2x⁵ + 0.04x⁴ - 0.0625x³ - 2x² + 0.3x + 4=0

The answer is 1.33. How would you figure it out without a computer?
In order to find all the roots of a polynome with a grade lower than 2, we need to know at least 1 root (this polynome has grade 5). We can try with the divisors of the constant (4 is the constant), which are: 1,-1,2,-2,4 and -4. But no, none of them verifies the equation! So it will be of hard to find a root. That’s because there are too many fractions, and a fraction can come from a variety of divisions. It’s even more difficult to find a root when there are irrational numbers among the roots (such as the square root of 2, or half a pi, or e). So, if we don’t know any of the roots, we can’t work with the Ruffini rule.

So in this case I suggest to put this in a graphic software:

y=-0.2x⁵ + 0.04x⁴ - 0.0625x³ - 2x² + 0.3x + 4

And there you have the plot. Then you click in “roots” and it will tell you the point: (1.33,0). So that’s how you know 1.33 is the answer.

A graphing calculator is used to determine the solution of an equation.

It is preferable when the equation is nonlinear.

There are several types of equations; some of them are:

Of these types of equations, the linear equation is the easiest.

It is of the form:

The above equation can be solved in two or three steps.

However, other types of equation (the nonlinear equations) often take time to solve.

So, the graphing calculators are preferred, over the conventional method for these types of equations.

Read more about graphing calculators at:

link

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