Question #b48d8

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Answer 1 · 2015-09-24T00:49:38

#x=2+isqrt(3),x=2-isqrt(3)#

This quadratic expression should be solved by completing the square.

#f(x)=x^2-4x+7=0#

Minus seven from both sides,

#x^2-4x=-7#

Add four to both sides,

#x^2-4x+4=-3#

Write the left hand side as a square,

#(x-2)^2=-3#

Take the square root of both sides,

#x-2=+-isqrt(3)#

Add two to both sides

#x=2+-isqrt(3)#

or

#x=2+isqrt(3),x=2-isqrt(3)#