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[Paps]

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The root of equation x2-6x-2=0 is ????
answer is 3 plus/minus root of 11
how do you do this problem...use the quadratic formula. i dont even know what theyre asking for. Thanks for anything

 

[luder98]

The root of equation x2-6x-2=0 is ????
answer is 3 plus/minus root of 11
how do you do this problem...use the quadratic formula. i dont even know what theyre asking for. Thanks for anything

For equation ax^2 + bx + c = 0, the solutions of the equation are

(-b +/- sqrt(b^2-4ac))/(2a), given b^2-4ac is positive. If not, there is no solution. If zero, one solution which is -b/(2a).

A special case is when b is an even number. First calculate b'=b/2. The solutions are then

(-b'+/-sqrt(b'^2-ac))/a, again, given b'^2-ac is positive.

PS: b' is not the derivative of b. I used it for naming purpose only.

If you don't want to memorize 2 formulas, just use the first. The second just make the calculation quicker and simpler.

 

[busdriver]

how do you do this problem...use the quadratic formula.

you got it! haha..just use the quadratic formula and you get the answer!!

 

[Paps]

thanks a lot....didnt know about the b'= b/2 when b is even. i just did the quadratic and kept ketting 6 +/- rt. 11

 

[busdriver]

u probably just forgot to divide the 6 by 2 as well...[6+/- (2)rt. 11]/2 = 3+/- rt.11