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Quadratic Equations
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30/05/2021 10:47 am
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Find the roots of the quadratic equations by applying the quadratic formula.
(i) 2x2 – 7x + 3 = 0
(ii) 2x2 + x – 4 = 0
1 Answer
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30/05/2021 10:52 am
(i) 2x2 – 7x + 3 = 0
On comparing the given equation with ax2 + bx + c = 0, we get,
a = 2, b = -7 and c = 3
By using quadratic formula, we get,
x = \(\frac{-b \pm \sqrt{b^2 -4ac}}{2a} \)
⇒ x = (7±√(49 – 24))/4
⇒ x = (7±√25)/4
⇒ x = (7±5)/4
⇒ x = (7+5)/4 or x = (7-5)/4
⇒ x = 12/4 or 2/4
∴ x = 3 or 1/2
(ii) 2x2 + x – 4 = 0
On comparing the given equation with ax2 + bx + c = 0, we get,
a = 2, b = 1 and c = -4
By using quadratic formula, we get,
x = \(\frac{-b \pm \sqrt{b^2 -4ac}}{2a} \)
⇒x = -1±√1+32/4
⇒x = -1±√33/4
∴ x = -1+√33/4 or x = -1-√33/4