How do you solve this? Find the values for c so that #x^2 + 2x + c = 0# will have two solutions

Find the values for c so that #x^2 + 2x + c = 0# will have two solutions
We did a problem like this during math class but I forgot how to do it and I can't find a good explanation for this.

1 Answer
Mar 18, 2018

#C<1#

Explanation:

I suggest you use the discriminant formula

In order to have two real solutions to a quadratic equation:
#B^2-4AC>0#

In order to have one real solution with multiplicity of two to a quadratic equation:
#B^2-4AC=0#

In order to have no real solution:
#B^2-4AC<0#

So in this case:
#(2)^2-4(1)C>0#

#4-4C>0#

#-4C>(-4)#

#C<1#