# Wolfram alpha giving wrong solutions?(link)

1. Jan 12, 2014

### Jarfi

So yeah, Just using wolfram to help draw a nice function, when this happens:

http://www.wolframalpha.com/input/?i=x^2/ln(x)

It shows a real part under zero, when the function given, x^2/ln(x) has no real solution under zero ! It's domain being:

Dm(f) = ]0;11;infinity[

need explanations fast.

2. Jan 12, 2014

### Staff: Mentor

$$\ln(-x) = \ln(-1 \times x) = \ln(-1) + \ln(x) = i \pi + \ln(x)$$

3. Jan 12, 2014

### Jarfi

This is the imaginary solution.

4. Jan 12, 2014

### Student100

I'm confused by the question, but if I understand right what's the of ln(.5), that would give you a negative solution.

If that's not what you mean select real valued plot, and not complex.

5. Jan 12, 2014

### Jarfi

It shows both the real and complex plot, however the real plot is drawn what seems incorrectly, it should stop at zero since x is not defined under zero for the real solution.

6. Jan 12, 2014

### Staff: Mentor

Then you don't understand what it shows - blue and red are imaginary and real parts of the complex solution, you have to switch to real valued plot (select it from the drop down).

7. Jan 12, 2014

### Student100

It's showing you the real and complex parts of the solution. You need to tab down to real valued plot.

8. Jan 12, 2014

### Jarfi

Ah, that makes sense. Thanks.