15. यदि समीकरण + x + 1 = 0 के मूल0 व 6 �

1.	15. यदि समीकरण + x + 1 = 0 के मूल0 व 6 हों, तो a + 62 बराबर है।(1) 1 (2) 2 (3) -1 (4) 1
Answer» zeroes of x^2 + x + 1 = 0are a and b Then,a + b = - 1ab = 1 Therefore value of a^2 + b^2 is (a + b)^2 = a^2 + b^2 + 2ab (-1)^2 = a^2 + b^2 + 2*1 a^2 + b^2 = 1 - 2 = -1 (3) is correct option

15. यदि समीकरण + x + 1 = 0 के मूल0 व 6 हों, तो a + 62 बराबर है।(1) 1 (2) 2 (3) -1 (4) 1

Answer»

zeroes of x^2 + x + 1 = 0are a and b

Then,a + b = - 1ab = 1

Therefore value of a^2 + b^2 is

(a + b)^2 = a^2 + b^2 + 2ab

(-1)^2 = a^2 + b^2 + 2*1

a^2 + b^2 = 1 - 2 = -1

(3) is correct option