Using quadratic eq solve x 2-12x+40=0?

Question

1586 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-06-08T12:48:41

#x=6+2i# and #6-2i#

As per the question, we have

#x^2-12x+40=0#

#:.# By applying the quadratic formula, we get

#x = (-b±sqrt(b^2-4ac))/(2a)#

#:.x = (-(-12)±sqrt((-12)^2-4(1)(40)))/(2(1))#

#:.x = (12±sqrt(144-160))/2#

#:.x =(12±sqrt(-16))/2#

Now, as our Discriminant ( #sqrt D # ) #< 0#, we're gonna get imaginary roots (in terms of #i# / iota).

#:.x=(12±sqrt(16)xxsqrt(-1))/2#

#:.x=(12±4 xx i)/2#

#:.x=(6±2i)#

#:.x=6+2i , 6-2i#

Note : For those who don't know, #i# ( iota ) = #sqrt(-1)#.