If two of the zeroes of the cubic polynomial ax3 + bx2 + cx + d are 0,

1.	If two of the zeroes of the cubic polynomial ax3 + bx2 + cx + d are 0, then the third zero is(a) \(\frac{-b}a\)(b) \(\frac{b}a\)(c) \(\frac{c}a\)(d) \(\frac{-d}a\)
Answer» (a) \(\frac{-b}a\) Let α , 0 and 0 be the zeroes of ax³ + bx² + cx + d = 0 Then the sum of zeroes = \(\frac{-b}a\) ⇒ α + 0 + 0 = \(\frac{-b}a\) ⇒ α = \(\frac{-b}a\) Hence, the third zero is \(\frac{-b}a\)

If two of the zeroes of the cubic polynomial ax3 + bx2 + cx + d are 0, then the third zero is(a) \(\frac{-b}a\)(b) \(\frac{b}a\)(c) \(\frac{c}a\)(d) \(\frac{-d}a\)

Answer»

(a) \(\frac{-b}a\)

Let α , 0 and 0 be the zeroes of ax³ + bx² + cx + d = 0

Then the sum of zeroes = \(\frac{-b}a\)

⇒ α + 0 + 0 = \(\frac{-b}a\)

⇒ α = \(\frac{-b}a\)

Hence,

the third zero is \(\frac{-b}a\)