SOLUTION: How would you solve problems like: x^2+5=0 x^2-11=0 Why is there two solutions? Thank you

Algebra.Com
Question 194972: How would you solve problems like:
x^2+5=0
x^2-11=0
Why is there two solutions?
Thank you

Answer by Alan3354(69443)   (Show Source): You can put this solution on YOUR website!
How would you solve problems like:
x^2+5=0
x^2-11=0
Why is there two solutions?
----------------------
x^2+5=0
Since there's no x term:

x = ± i*sqrt(5) where i = sqrt(-1)
---------------------------------
x^2-11=0

x = +sqrt(11)
x = -sqrt(11)
-----------------
There are 2 solutions because both work.
In the 2nd eqn, both +sqrt(11) and -sqrt(11) are 11 when they're multiplied by themselves.
----------
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation (in our case ) has the following solutons:



For these solutions to exist, the discriminant should not be a negative number.

First, we need to compute the discriminant : .

Discriminant d=44 is greater than zero. That means that there are two solutions: .




Quadratic expression can be factored:

Again, the answer is: 3.3166247903554, -3.3166247903554. Here's your graph:

-------
If you graph them, you'll see that they cross the x-axis in 2 places (the 2nd one).
You can get FREE software to graph these at
www.padowan.dk.com/graph/

RELATED QUESTIONS

How would you solve problems like: x^2-25=0 x=.... x^2-49=0 x=.... Thank... (answered by bsmath)
How would you solve these two problems using completing the square? 4x^2+32x+20=0 &... (answered by solver91311)
I would like to know how TO solve -2+x/5-3=0 I already know the answer. thank... (answered by josgarithmetic)
Hello! I would like to know how to solve for x in this log problem. log(2x+5) *... (answered by richwmiller)
The product of two consecutive odd integers is 22 more than 7 times the larger number.... (answered by Seutip,MathTherapy)
Algebra: How would you plot the second line and why would you plot it like that is there... (answered by jim_thompson5910)
Find all real solutions: x-5x^1/2+4=0 How would you solve this... (answered by mananth)
How do I solve these two logarithms. I have the problems 5 ^x-1/3 = power 3 square (answered by josgarithmetic,MathTherapy)
hi, how do i solve these two problems? 3e^-x-4=9 & 5log(x-2)=11 is there a like... (answered by jsmallt9)