Question

find the double root of x³-5.4x^2+9.24x-5.096=0 given that it is near to 1.5.
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Answer 1

Answer:

Since, one root is 1, then x=1

⇒  3(1)2+a(1)−2=0

⇒  3+a−2=0

⇒  a+1=0

⇒  a=−1

⇒  Now, it is given that ax2+6ax−b=0 has equal roots.

∴  b2−4ac=0

⇒  (6a)2−4(a)(−b)=0

⇒  36a2+4ab=0

⇒  36(−1)2+4(−1)b=0                 [ Substituting a=−1 ]

⇒  36−4b=0

⇒  4b=36

∴  b=9

Answer 2

Answer:

Explanation:

Since, one root is 1, then x=1

Vol 97

b2-4ac=0

Vol 97

(6a)2-4(a)(-b)=0

→ 36a2+4ab=0

→ 36(-1)2+4(-1)b=0

[Substituting a=-1]

→ 36-4b=0

⇒ 4b=36

:: b=9

→ 3(1)2+a(1)-2=0

⇒ 3+a-2=0

a+1=0

⇒a=-1

→ Now, it is given that ax2+6ax-b=0 has equal roots.

.. b2-4ac=0

(6a)2-4(a)(-b)=0

36a2+4ab=0

36(-1)2+4(-1) b=0