Question

Solve 4x² +7x +2 = 0. Giving the answer correct to 2 decimal places.​

Answer 1

Answer:

The roots are -0.36 and -1.39.

Step-by-step explanation:

The roots of a quadratic equitation ax² + bx + c = 0 is:

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

Here,

a = 2

b = 7

c = 2

Compute the roots as follows:

$x = \frac{ -7 \pm \sqrt{7^2 - 4(4)(2)}}{ 2(4) }\\x = \frac{ -7 \pm \sqrt{49 - 32}}{ 8 }\\x = \frac{ -7 \pm \sqrt{17}}{ 8 }\\x = \frac{ -7 }{ 8 } \pm \frac{\sqrt{17}\, }{ 8 }\\x= -0.36,\ \ x=-1.39$

Thus, the roots are -0.36 and -1.39.

Answer 2

Answer:

-0.36 and -1.39

Step-by-step explanation:

by applying quadratic equation formula,

-7±√49 - 4(4)(2) / 2(4)

=> -7 ± √49-32 / 8

=> -7 ± √17 / 8

=> -7 ± 4.12 / 8

taking + ve value,

-7 + 4.12 / 8 = -0.36

taking -ve value,

-7 - 4.12 / 8 = -1.39