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Solving Quadratics Recap

METHOD 2: Square Root Trick

*Works great when the middle x term is missing.
Don't forget the  +/-  !

example:

Solve   4x^2 - 5 = 0

 

get x^2 alone: 4x^2 = 5 gives x^2 = 5/4 which gives sqrt( x^2 ) = +/- sqrt( 5/4 ) = +/- sqrt( 5 ) / sqrt( 4 ) = +/- sqrt( 5 ) / 2

{ -sqrt( 5 ) / 2 , sqrt ( 5 ) / 2 }

YOUR TURN:

Solve  9x^2 - 17 = 0