How do you find the roots, real and imaginary, of #y= -7x^2 -15x +(x-3)^2 # using the quadratic formula?

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Answer 1 · 2017-08-17T13:31:45

see below

#-7x^2 -15x +(x-3)^2=0#

#=>-6x^2-21x+9=0#

#=>6x^2+21x-9=0#

#a=6, b=21, c=-9#

#x=(-21+-sqrt((21)^2-(4*6*(-9))))/(2*6)=(-7+-sqrt(73))/(4)#

Hence, there are no imaginary roots, both are real and distinct.