Solve the equation t^2+10=6t by completing square method?

1 Answer
Oct 27, 2016

t=3-i or t=3+i

Explanation:

t^2+10=6t can be written as

t^2-6t+10=0

or t^2-6t+9+1=0

Now we use the identity (x+1)^2=x^2+2x+1 and imaginary number i defined by i^2=-1

or t^2-2xx3t+3^2-(-1)=0

or (t-3)^2-i^2=0

Now using identity a^2-b^2=(a+b)(a-b), this becomes

(t-3+i)(t-3-i)=0

Hence, either t-3+i=0 i.e. t=3-i

or t-3-i=0 i.e. t=3+i