Question 201168
 y= -3x^2 +4x -1
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differentiate  and  set  equal  to  zero
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y' = -6x +4
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-6x +4 =0
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-6x =-4
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x= 2/3,,,,,,,
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substitute into  original  eqn
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y = -3(2/3)^2 +4(2/3) -1
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y= -3 (4/9) +8/3 -3/3
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y= -4/3 +8/3 -1/3
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y = 1/3,,,,,,,,
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Checking  points  in  proximity, ( 0,-1) and  (1,0)  confirm  a  downward  pointing  y  parabola  ,  with  a  vertex  at  (2/3,1/3)  which  is  a  max
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