Question

Find the roots of 4x2 + 3x + 5 = 0 by the method of formula method.​

Answer 1

$4x^{2}+3x+5=0\\\\a=4\\b=3\\c=5$

Formula,

$x=\frac{-b(+-)\sqrt{b^{2}-4ac } }{2a}$

$x=\frac{-b+\sqrt{b^{2}-4ac } }{2a}$ and $x=\frac{-b-\sqrt{b^{2}-4ac } }{2a}$

Now, put values and find roots....

$x = \frac{-3+\sqrt{(-3)^{2}-4(4)(5) } }{2(4)}$ and $x = \frac{-3-\sqrt{(-3)^{2}-4(4)(5) } }{2(4)}$

$x=\frac{-3+\sqrt{9-80} }{8}$ and $x=\frac{-3-\sqrt{9-80} }{8}$

$x=\frac{-3+\sqrt{-71} }{8}$ and $x=\frac{-3-\sqrt{-71} }{8}$

Roots are complex