# Complex Roots (Imaginery Numbers) Answers With Sharp El-W519X

1. Jul 9, 2014

### sammy134

Ive had this problem with the calculator since I bought it. It might be that the calculator does not have enough implemented functions to pull it off or I am missing something. It happens when I am solving for imaginery roots.

Example: y^2 + y^1+y = 0.

I go to mode, and select 6(equation) and than select 2 (quadratic). I put in a = 1, b = 1, c = 1. I get the answer -0.5 +/- 0.866025403i

Now I understand that this is the correct answer thats not my problem. I am currently taking Differential Equations math course and when I am finding the homogenous answer to a solution with complex roots I need to be able to state the answer in FRACTION form. The correct fraction form is SQRT(3)/2. Now normally if I type in SQRT(3)/2 I change between 0.866025403 and SQRT(3)/2. But if I type in 0.866025403 and press =, I cant change to SQRT(3)/2 because its not the exact amount of decimals. I need to be able to give the answer as -0.5 +/ SQRT(3)/2. So that I can use it to give the homogenous answer to the solution being e^-1/2*(c1*cos(SQRT(3)/2) + (c2*sin(SQRT(3)/2). Usually hitting the "change" button rotates between the Fraction form and the decimal form of an answer, but I cant use change button under the equation, quadratic solver. It does nothing when I hit it.

Now my question is, 1) is there anything else that I can do to fix my problem, and 2) if there is nothing I can do, is there a more advanced brand of SHARP that I can buy, maybe one with more implemented fuctions, if that is the problem. Keep in my mind that it still has to be not advanced as a graphing because I need to be able to use it on exams.

Thank you!

2. Jul 10, 2014

### Simon Bridge

The calculator is displaying fewer DP than it stores for it's calculations.
All calculators will have this problem because they would otherwise have to be able to guess which fraction your string of decimals is approximating. (does it make the right guess for 0.3333333333?)

There are computers capable of that sort of thing - what you need is something advanced enough to be self-aware. These things can be quite pricey to maintain and hard to program reliably, but well worth the effort. Fortunately almost all of us are born with one.

Enjoy :)