Homework Statement
Solve for X
Homework Equations
x^2 + x + 1 > 2The Attempt at a Solution
x2 + x - 1 > 0
(x + 2)(x - 1/2) > 0
x > 2
x > 1/2
Wolfram Alpha said that the solutions for X are:
x>1/2 (sqrt(5)-1)
and
x<1/2 (-1-sqrt(5))
what did I do wrong?
Homework Statement
2. What is wrong with the following "proof"? Let x = y. Then
x2 =xy,
x2 - y2 =xy - y ,
(x + y)(x -y) = y(x - y),
x + y = y,
2y = y,
2= 1.Homework Equations
It's obvious that x + y =/= y, but I do not know how to "prove" this, i.e. which proof from algebra is applicable...