(v) n2 + 4n = 0, n = 0, – 2, – 4
Sol. a) By putting n = 0 in L.H.S. we get
L.H.S. = (0)2 + 4(0)
= 0 + 0
= 0
= R.H.S.
∴ L.H.S. = R.H.S.
Thus equation is satisfied.
So, 0 is the root of the given quadratic equation.
b) By putting n = –2 in L.H.S. we get
L.H.S. = (– 2)2 + 4(– 2)
= 4 – 8
= – 4
≠ R.H.S.
∴ L.H.S. ≠ R.H.S.
Thus equation is not satisfied.
So, –2 is not the root of the given quadratic equation.
c) By putting n = –4 in L.H.S. we get
L.H.S. = (– 4)2 + 4(– 4)
= 16 – 16
= 0
= R.H.S.
∴ L.H.S. = R.H.S.
Thus equation is satisfied.
