Question

What is the value of m, if the equation my2+2y−4=0 has exactly one root?

Answer 1

Answer:

$m=\frac{-1}{4}$

Step-by-step explanation:

A quadratic equation has one root if the discriminant is 0.

That is we need $b^2-4ac=0$ for this particular question.

Compare the following to find $a,b, \text{ and } c$:

$ax^2+bx+c=0$

$my^2+2y-4=0$

The variable $x$ is representative of the variable $y$ here.

$a=m$

$b=2$

$c=-4$

Plug in into $b^2-4ac=0$:

$(2)^2-4(m)(-4)=0$

$4+16m=0$

Subtract 4 on both sides:

$16m=-4$

Divide both sides by 16:

$m=\frac{-4}{16}$

Reduce:

$m=\frac{-1}{4}$

Answer 2

Answer:

m = -1/4

Step-by-step explanation:

B²-4AC = 0 when one real root

(2)² - 4(m)(-4) = 0

4 + 16m = 0

m = -4/16

m = -1/4