+91-8076753736[email protected]
logo
logo
-->

Complex Numbers And Quadratic Equations

Question
CBSEENMA11015666
Wired Faculty App

If one root of the equation x2+px+12 =0 is 4, while the equation x2 +px +q = 0 has equal roots, then the value of 'q' is

  • 49/3

  • 4

  • 3

  • 12

Solution

A.

49/3

Since 4 is one of the roots of equation x2 + px + 12 = 0. So it must satisfied the equation.
∴ 16 + 4p + 12 = 0
⇒ 4p = -28
⇒ p = -7
The other equation is x2 - 7x + q = 0 whose roots are equal. Let roots are α and α of above equation
therefore space sum space of space roots space equals straight alpha space plus straight alpha space equals 7 over 1
⇒ 2α = 7 ⇒ α = 7/ 2 and product of roots α.α = q ⇒ α2 = q

(7/2)2 = q
q =49/4

Some More Questions From Complex Numbers and Quadratic Equations Chapter

All the values of m for which both roots of the equations x2 − 2mx + m2 − 1 = 0 are greater than −2 but less than 4, lie in the interval

If the cube roots of unity are 1, ω, ω2 then the roots of the equation (x – 1)3 + 8 = 0, are

The value of α for which the sum of the squares of the roots of the equation x2 – (a – 2)x – a – 1 = 0 assume the least value is

If roots of the equation x2 – bx + c = 0 be two consectutive integers, then b2 – 4c equals

If z1 and z2 are two non-zero complex numbers such that |z1 + z2| = |z1| + |z2| then argz1 – argz2 is equal to

Mock Test Series

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation