Question: How can I validate if an object is of a certian class? I currently use 

```
get_class($obj) == 'User';

```

But it may look like `\KM\User` when I am elsewhere? I think this way maybe abit prone to developer error. Is there something like:

```
compare_class($obj1, User);
// or maybe
classof($obj) == User;

```

Answer: 
You can simply compute verything before:

plot 25-20+((2Pi0.3²)/(Pi10²)Sqrt[2\*980(1+(Pi10²)/(Pi10²))]t)² from 0 to 38

or

plot 25-20+((2\*0.3²)/(10²)Sqrt[2\*980(1+1)]t)² from 0 to 38

or 

25 - 20 + 4 \* 0.0000081 \* 3920\*t^2 from 0 to 38 (I have some factor wrong, but you get the idea)

just apply basic math to the constants and remove the middle (imaginary part) after applying the 2nd binomic formula.

There is nothing to do with complex numbers.
It's not right to say that "Java can't handle it". No language that returns a double from a square root can handle it, but if you have a `Complex` class it's not an issue. Python has one built in; it's easy to write one in Java.