If x = 1 + 21/2 and y = 1 – 21/2, then x2 + y2 is

• x2 + y2 = (x+y)^2 - 2(xy)
  =>(2)^2 - 2(1-(21/2)^2)
  => 4-2(4-441)/4
  =>4-(437/2)
  =>(8+437)/2
  =>445/2 = 222.50
• 6 years agoHelpfull: Yes(1) No(1)
• Ans: 6
  X = 1 + 2^1/2 = 1 + sqrt(2)
  Y = 1 - 2^1/2 = 1- sqrt(2)
  X^2 = ( 1 + sqrt(2) )^2
  = 1 +2 + 2 * 1 * sqrt(2) ( (a+b)^2 = a^2 + b^2 + 2ab )
  = 3 + 2 * sqrt(2)
  Y^2 = ( 1 - sqrt(2) )^2
  = 1 + 2 - 2 * 1 * sqrt(2) ( ( a-b)^2 = a^2 + b^2 - 2 * a * b )
  = 3 - 2 * sqrt(2)
  
  X^2 + Y^2 = 3 + 2 * sqrt(2) + 3 - 2 * sqrt(2)
  = 6
• 4 years agoHelpfull: Yes(1) No(0)