Why Does the Quadratic Formula Give Unexpected Graph Results?

[Firepanda]

Applying it to

-x² - bx +c = 0

I would have thought it to be

(b +- (b²+4c)^0.5) /-2

= (-b +- (b²+4c)^0.5) /2


But

Anytime I try and graph a function like it the roots are

(b +- (b²+4c)^0.5) /2

I can't see why this is?

Thanks

 

[Mark44]

Applying it to

-x² - bx +c = 0

I would have thought it to be

(b +- (b²+4c)^0.5) /-2

= (-b +- (b²+4c)^0.5) /2

Yes, the roots of the equation above are x = (-b +- (b²+4c)^0.5) /2.

But

Anytime I try and graph a function like it the roots are

(b +- (b²+4c)^0.5) /2

I can't see why this is?

Thanks

I can't either, but I suspect you're doing some unconscious sign-changing of the coefficients when you enter the function into whatever graphing utility you're using.

Regarding your first equation, why don't you multiply both sides by -1 to get x^2 + bx - c = 0? The solutions would be the same.