Quadratic Formula

We must use the quadratic formula when an equation cannot be factored. Yes?

 

yes

 

To use a quadratic equation, the equation must be in the form ax^2 + bx + c = 0, where a = b = c = constants.

 

NO! We can "complete the square"!

For example, x^2- 8x+ 3= 0 cannot be factored. But it can be written as x^2- 8x= -3. "Complete the square" by adding 16 to both sides: x^2- 8x+ 16= -3+ 16.
(x- 4)^2= 13.
x- 4= +/- sqrt(13).

The solutions are x= 4+ sqrt(13) and x= 4- sqrt(13).

Of course, those are the solutions the quadratic formula would give us.

 

You mean "to use the quadratic formula".

And any quadratic equation can be easily put in that form.

 

You said no but MathLover1 said yes. Now, I am confused.

 

Yes, of course to use in the quadratic formula.