Question

find the value of a and b from following quadratic equations x2-7x+5=0 ​

Answer 1

Answer :-

General form of quadratic equation = ax² + bx + c

Here,

• a is called coefficient of x²
• b is called coefficient of x
• c is called constant

Now,

Given quadratic equations = x² - 7x + 5 = 0

Here,

• Coefficient of x² is 1

So, value of a = 1

• Coefficient of x is -7

So, value of b = -7

Hence,

• a = 1
• b = -7

Additional information :-

Roots of the quadratic equation ax² + bx + c = 0 are -

$\sf\dfrac{-b + \sqrt{b^2-4ac}}{2a} \:and \:\dfrac{-b - \sqrt{b^2-4ac}}{2a}$

Nature of the factors of the quadratic expression.

1. If b² - 4ac > 0 then roots are real and different.

2. If b² - 4ac is a perfect square, then roots are rational and different.

3. If b² - 4ac = 0, then roots are real and equal

4. If D < 0 then, roots are imaginary and unequal or complex conjugate.