These days on the ACT most calculator applications and programs are not legal to have during the test. However, all of the normal features of a Texas Instruments graphing calculator are perfectly legal and in some instances can help save a few precious seconds on the math section of this important college placement test.
Being able to factor polynomials is a crucial skill to get any student through their high school math courses. In most Algebra 2 courses across the country, an entire unit is dedicated to solving quadratics. While a TI-84 graphing calculator does not have the capabilities of giving answers as simplified radicals (if the answer happens to be an irrational number), it can provide students with answers in decimal or whole number form.
The most common way to find the roots of a quadratic equation in a graphing calculator is to actually graph the quadratic equation that you are given. Simply go to Y= and input the function you are working with in your given problem. Hitting the ZOOM 6 or GRAPH keys on your TI-84 or TI-83 will yield a picture of the parabola of your quadratic. Next, hit 2nd TRACE and scroll down to the key that says, ZERO. Your high school Algebra teacher has probably mentioned to you before that roots, zeros, x-intercepts and solutions are all interchangeable when talking about quadratics.
After going through the steps above, you should be back to the picture of your parabola with the words, “left curve” given. This means you need to hit the left arrow key to move your blinking cursor to the left of one of the roots of your quadratics. Hit enter and then you will be prompted to move your cursor to the right of the said root. Hit enter twice more and you will be given an approximate solution. Depending on how far left and right you moved your cursor will depend on how accurate the answer will actually be. Repeat the above process as many times as roots that you have in your given problem. Of course, if you are dealing with a quadratic you will have at most 2 roots. If it is a cubic, then you will have three roots. If you can follow these steps, then it will greatly increase your accuracy in your current math course and maybe even help out on the ACT math section.