Melody

try pressing the - button. 

So you found that (0,0) is one solution - that is certainly correct:)

I got

x approx 7.39 and x approx 54.6

Here it the graph that i used.

Think about it

sine of an angle is opposite over hypotenuse in a right angled triangle.

The hypotenuse is the longest side so sine of the angle cannot be more than 1!

Is 18 to the power of 6 or to the power of 6x?

It is good to use brackets :)

why dont you actually give us a polynomial question. ?

Why dont you google it and come back and tell us the answer?

or just 20/100*6.87

$${\frac{{\mathtt{20}}}{{\mathtt{100}}}}{\mathtt{\,\times\,}}{\mathtt{6.87}} = {\frac{{\mathtt{687}}}{{\mathtt{500}}}} = {\mathtt{1.374}}$$

1/100*230 000 000 000

now do it on the calc on the home page.

I like the way you have done that with a little computer program. I assume that is how you did it.