Question

Use the quadratic formula to solve the equation -3x2-x-3=0

Answer 1

Answer:

$x=\frac{1+\sqrt{35}i}{-6}\,\, and\,\, x=\frac{1-\sqrt{35}i}{-6}$

Step-by-step explanation:

the quadratic formula is:

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

a= -2, b = -1 and c =-3

Putting values in the formula

$x=\frac{-(-1)\pm\sqrt{(-1)^2-4(-3)(-3)}}{2(-3)}\\x=\frac{1\pm\sqrt{-35}}{-6}\\x=\frac{1+\sqrt{-35}}{-6}\,\, and\,\, x=\frac{1-\sqrt{-35}}{-6}\\We\,\, know \,\,that \,\,\sqrt{-1} = i \\x=\frac{1+\sqrt{35}i}{-6}\,\, and\,\, x=\frac{1-\sqrt{35}i}{-6}$

So, $x=\frac{1+\sqrt{35}i}{-6}\,\, and\,\, x=\frac{1-\sqrt{35}i}{-6}$

Answer 2

Answer:

Using quadratic formula, the solution to this equation is  the roots of the equations given are ;   x = 1+√35i /  -6   or                x = 1-√35i /  -6

Step-by-step explanation:

-3x²  -  x   - 3=0

To solve this using quadratic formula, we will first of all write down the quadratic formula

x = -b ±√b²- 4ac   /   2a

From the above question;

a = -3    b = -1  and c=-3

So we can now proceed to plug-in our variable

x = -(-1) ± √(-1)² - 4(-3)(-3)    /      2(-3)

x=  1±√1-36   /   -6

x = 1 ±√-35    /  -6

x=1 ± √35  ·  √-1    /-6

x = 1±√35 i    /     -6

Note the square root of negative 1 is i

Either x = 1+√35i /  -6   or   x = 1-√35i /  -6

Therefore the roots of the equations given are ;   x = 1+√35i / -6   or   x = 1-√35i /  -6