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Help needed asap 20 points if answered right

Help needed asap 20 points if answered right-example-1
User WayneZhao
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1 Answer

4 votes

ANSWER

1. No real roots

2.
( 7\pm \: √(33) )/( - 4)

3. The discriminant is negative.

Step-by-step explanation

1. The given equation is


- 2 {x}^(2) - 9x - 5 = 0

We have a=-2,b=-9 and c=-5.

The discriminant is given by:


D= {b}^(2) - 4ac


D= {( - 9)}^(2) - 4( - 2)( - 5)

This simplifies to:


D= 36 - 40 = - 4

Since the discriminant is less than zero, the quadratic equation has no real roots.

2. The given equation is:


- 2 {x}^(2) - 7x - 2= 0

We have a =-2, b=-7 and c=-2.

The roots of this equation are given by;


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

We plug in the values to get;


x = \frac{ - - 7\pm \: \sqrt{ {( - 7)}^(2) - 4( - 2)( - 2) } }{2( - 2)}


x = ( 7\pm \: √(33) )/( - 4)

3. The given graph is hanging downwards. This means that it doesn't have x-intercepts.

Therefore the roots are complex or imaginary.

This implies that, the discriminant of the corresponding equation is negative.

User Dan Jay
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