Thread: Quadratic Equation general question

As we know the standard form of a quadratic equation is

But when B is equal to 0 in the above it looks like this . However to get the c in the preceding to look like a standard quadratic equation you must add its inverse to the other side.

Take this for example

Obviously you could just do the to get +- 7. But What if you wanted to put it in general quadratic form?

If I wanted to put it general quadratic form would this be correct?



Then just use the multiplicative property of zero to solve both equations and arrive at +- 7?

So in conclusion has my reasoning and calculations been correct up to this point?

Many thanks!

Originally Posted by cmf0106

As we know the standard form of a quadratic equation is

But when B is equal to 0 in the above it looks like this . However to get the c in the preceding to look like a standard quadratic equation you must add its inverse to the other side.

Take this for example

Obviously you could just do the to get +- 7. But What if you wanted to put it in general quadratic form?

If I wanted to put it general quadratic form would this be correct?



Then just use the multiplicative property of zero to solve both equations and arrive at +- 7?

So in conclusion has my reasoning and calculations been correct up to this point?

Many thanks!

Um, yeah, pretty much

Originally Posted by cmf0106

As we know the standard form of a quadratic equation is

But when B is equal to 0 in the above it looks like this . However to get the c in the preceding to look like a standard quadratic equation you must add its inverse to the other side.

Take this for example

Obviously you could just do the to get +- 7. But What if you wanted to put it in general quadratic form?

If I wanted to put it general quadratic form would this be correct?



Then just use the multiplicative property of zero to solve both equations and arrive at +- 7?

So in conclusion has my reasoning and calculations been correct up to this point?

Many thanks!

Yes, up to now your conclusion has been correct, but even more generally

in if we let

then by the quadratic formula the solution is



Which shows the fact that for a case where b=0 one of the two must have a negative coefficient otherwise ti would yield an imaginary result