Question

x2-4x-4=0 using quadratic formula​

Answer 1

Answer:

${x}^{2} - 4x + 4 = 0 \\ standard \: form : \\ a{x}^{2} + bx + c = 0 \\ a = 1 \\ b = - 4 \\ c = 4 \\ by \: using \: quadratic \: equation : \\ distriminant \: (d) \\ = {b}^{2} - 4ac \\ = {( - 4)}^{2} - 4(1)(4) \\ = 16 - 16 = 0 \\ so \: it \: has \: equal \: roots .....(i)\\ let \: x \: = \alpha \: or \: x = \beta \\ \alpha = \beta \: \: (from \: eq(i)) \\ \alpha = \frac{ - b + \sqrt{d} }{2a} = \beta = \frac{ - b- \sqrt{d} }{2a} \\ \\ \alpha = \beta = \frac{ - ( - 4)}{2} = 2 = x$