Question

Find the roots of quadratic equation 2xsquare-√5x-2=0 using the quadratic formula.

Answer 1

Equation : 2x² - √5 x - 2 = 0,


On comparing the given equation with { ax² + bx + c = 0 }, we get that the value of a is 2 , value of b is √5 and value of c is - 2




$Quadratic \: \: formula : x = \frac{ -b \pm \sqrt{ b^{2}- 4ac}}{ 2a }$



Applying formula ,



$= > x = \frac{ - 5 \pm \sqrt{( \sqrt{5}) {}^{2} - 4(2 \times - 2) } }{2 \times 2} \\ \\ \\ \\ = > x = \frac{ - 5 \pm \sqrt{5 + 16} }{4} \\ \\ \\ \\ = > x = \frac{ - 5 + \sqrt{21} }{2} \: \: \: \: or \: \: \: \: \: x = \frac{5 - \sqrt{21} }{2}$