Question

Evaluate the discriminant of -3x2+5-4=0

Answer 1

-23

Explanation:

A quadratic equation is given to us and we are interested in finding the discriminant of the quadratic equation . As we know that ,

If the quadratic equation is in Standard form ,

`\sf\longrightarrow ax^2+bx + c = 0`

The discriminant is ,

`\sf\longrightarrow D = b^2-4ac`

The given quadratic equation is ,

`\sf\longrightarrow -3x^2 +5x - 4 = 0`

On comparing it with the Standard form , we have ,

• a = (-3)
• b = 5
• c = (-4)

So that ,

`\sf\longrightarrow D = (5)^2 - 4(-3)(-4)\\`

`\sf\longrightarrow D = 25 - 48\\`

`\sf\longrightarrow \bf D = -23`

Also note that if D < 0 , then the roots are complex conjugates .

Hence the discriminant is (-23).