Question

radical din x+1 = x-1

Answer 1

Se pune conitia de existenta a radicalului si anume:

x+1≥0 => x≥-1 => x∈[-1,∞)

√(x+1)=x-1/² (ridicam la parat egalitatea)

x+1=(x-1)²

x+1=x²-2x+1

x²-3x=0

x(x-3)=0

x=0∈[-1,∞)

x=3∈[-1,∞)