Solve the quadratic equations by factorization method only 21x2 + 9x + 1 = 0

Asked by Sakshi | 1 year ago |  49

##### Solution :-

Given: 21x2 + 9x + 1 = 0

We shall apply discriminant rule,

Where, $$x= \dfrac{-b\pm \sqrt{b^2-4ac}}{2a}$$

Here, a = 21, b = 9, c = 1

So,

$$x=\dfrac{(-9 ±\sqrt{(9^2 – 4 (21)(1)))}}{2(21)}$$

= $$\dfrac{ (-9 ± \sqrt{3(-1))}}{42}$$

We have i2 = –1

By substituting –1 = i2 in the above equation, we get

$$x=\dfrac{(-9 ± \sqrt{3i^2)}}{42}$$

= $$-\dfrac{3}{14}±\sqrt{\dfrac{3i}{42}}$$

The roots of the given equation are $$-\dfrac{3}{14}±\sqrt{\dfrac{3i}{42}}$$

Answered by Aaryan | 1 year ago

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