Question

A and B are the two zeroes of polynomials ax²+bx+c. Find the value of

A²+B².​

Answer 1

Step-by-step explanation:

A + B = -b/c

AB = c/a

now (A + B)² = A² + B² + 2AB [ identity ]

=> [-b/a]² = A² + B² + 2*c/a

=> b²/a² = A² + B² + 2c/a

therefore A² + B² = b²/a² - 2c/a

=> A² + B² = [b² - 2ac]/a²