How do you solve using the completing the square method #a²-a-1=0#?
1 Answer
Mar 21, 2016
Explanation:
First multiply the whole equation by
#0 = 4a^2-4a-4#
#= 4a^2-4a+1-5#
#= (2a-1)^2-(sqrt(5))^2#
#= ((2a-1)-sqrt(5))((2a-1)+sqrt(5))#
#= (2a-1-sqrt(5))(2a-1+sqrt(5))#
Hence:
#a=(1+-sqrt(5))/2#
