How do I solve for X in this formula scratching my head

[born2dive00]

0.5*(.00042672810819+SIGN(.00042672810819)*SQRT(.000426728108192^2-4*1*X))

=-0.0245173109651187

Please let me know thank you.

 

[Deleted member 4993]

0.5*(.00042672810819+SIGN(.00042672810819)*SQRT(.000426728108192^2-4*1*X))

=-0.0245173109651187

Please let me know thank you.

What does SIGN mean here?

 

[Dr.Peterson]

0.5*(.00042672810819+SIGN(.00042672810819)*SQRT(.000426728108192^2-4*1*X))

=-0.0245173109651187

I would guess that SIGN means the signum function; with a positive argument, the value of this function is +1.

Now the equation looks like the quadratic formula, with a=1, b=-.00042672810819, c=X, and x= -0.0245173109651187. So you could just write the quadratic equation whose solution it gives, and rearrange to solve for c.

Or, you could just solve as usual, doing some multiplication, subtraction, squaring, and so on. What have you tried?

In any case, to avoid trouble with those messy numbers, I would replace them with variables while doing the solving.

Please show work, as we request in the guidelines you probably didn't read. There is a good summary here. I'm curious as to the context of your question.

 

[Steven G]

0.5*(.00042672810819+SIGN(.00042672810819)*SQRT(.000426728108192^2-4*1*X))

=-0.0245173109651187

Please let me know thank you.

Where are you stuck? What have you tried? This forum offers help, not solutions.

I will supply a start. You should 1st multiply both sides by 2 and then compute SIGN(.00042672810819).