Question

If a and d are the roots of the quadratic equation x²+x+1=0 , then find the value of 1/a + 1/b​

Answer 1

$\to \sf{\green{x^2+x+1=0}}$

Now, a and b are roots.

We need to find 1/a + 1/b.

$\sf \dfrac{1}{a} +\dfrac{1}{b}$

$\sf \dfrac{a+b}{ab}$

Now, find a+b.

⇒ a+b = -b/a

⇒ a+b = -1/1 ⇒ -1

Also, ab will be:

⇒ ab = c/a

⇒ ab = 1/1 = 1.

So,

$\sf \dfrac{a+b}{ab}$

$\to \sf - \dfrac{1}{1}$