Question

Find the least positive value of k for which the equation x^2+kx+4=0 has real roots

Answer 1

The equation is x2 + kx+the real roots r x=+-4

Answer 2

Answer:

The least value of k is 4.

Step-by-step explanation:

The given equation is

$x^2+kx+4=0$

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

$b^2-4ac\geq 0$

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

$k^2-16\geq 0$

$k^2\geq 16$

$k\geq 4$

The value of k must be greater than 4, therefore the  least value of k is 4.