Question

Find the least positive value of k for which the equation square+kx+4=0 has equal roots

Answer 1

When roots are equal, the discriminant is 0

so, D = 0

Answer 2

Given:-

• the equation x²+kx + 4 = 0 has real roots.

To find:-

• Find the value of k.?

Solutions:-

• The given quadratic equation is x²+kx + 4 = 0 and roots are real.

Here,

• a = 1
• b = k
• c = 4

We know that;

• D => b² - 4ac

Putting the value of a = 1, b = k and c = 4

• D => b² - 4ac

=> (k)² - 4 × 1 × 4

=> k² - 16

The given equation will have real and equal root,

• D = 0

=> k² - 16 = 0

Now factroizing of the above equation.

=> k² - 16 = 0

=> k² = 16

=> k = √16

=> k = +,- 4

Now,

• the value of k is positive.

Hence, the value of k is 4.