HELP plz! (1 Viewer)

[nonothing234]

omg! i need help on figuring out this question...
What are the roots of...
y=x^2 - 4 - 11



i made it all colorful
too! someone plz answer my
question!


​

 

[-pari-]

is that meant to be y = x^2 - 4x - 11

?

 

[nonothing234]

oh yea thats what i meant
sorry i was in a hurry
y=x^2 - 4x - 11
​

 

[LoneShadow]

Roots of the equation occurs when the graph cut/touches the x-axis. When this happens, y is zero:

y = x^2 - 4x -11 = 0

You can use either quadratic equation or complete the square. I hate the former:

x^2 -4x = 11

x^2 - 4x + 4 = 11 + 4
(x-2)^2 = 15
x-2 = +/- Sqrt(15)
x = 2+/- Sqrt(15)

 

[nonothing234]

thnx ur a BIG help!​

 

[LoneShadow]

I'm not fat :mad1: