Question

if x=7+√40find the value of√x+1/x​

Answer 1

Answer:

x=7+√40

=7+2√10

=5+2+2√10

=(√5)²+2.√5.√2+(√2)²

=(√5+√2)²

∴√x=√5+√2 (neglecting the negative sign)

1/√x=1/(√5+√2)

=(√5-√2)/(√5+√2)(√5-√2)

=(√5-√2)/(5-2)

=(√5-√2)/3

√x+1/√x

=(√5+√2)+(√5-√2)/3

=(3√5+3√2+√5-√2)/3

=(4√5+2√2)/3

=2(2√5+√2)/3