Question

If root 11 + root 7 by root 11 - root 7 = a + b root 72 find the value of a and b

Answer 1

{√11+√7}/{√11-√7}=a+b√77

solving L.H.S

multiplying it with

{√11+√7}/{√11+√7}

we get

{√11+√7}^2/(√11)^2-(√7)^2

as we know that

(x+y)^2=x^2+y^2+2xy

so

=(11+7+2√77)/(11-7)

=18+2√77/4

=9+√77/2

so a+b√77=(9/2)+1/2×(√77)

so a= 9/2

b=1/2