Question

For what value of k the quadratic equation x2+4x+k=0 has real roots

Answer 1

★ QUADRATICS RESOLUTION ★

Answer 2

Answer:

The value of k must be less than or equal to 4.

Step-by-step explanation:

The given quadratic equation is

$x^2+4x+k=0$

A quadratic equation $ax^2+bx+c=0$ has real roots if

$b^2-4ac\geq 0$

We have,

$a=1,b=4,c=k$

$(4)^2-4(1)(k)\geq 0$

$16-4k\geq 0$

$16\geq 4k$

Divide both sides by 4.

$4\geq k$

Therefore the value of k must be less than or equal to 4.