w2 - 2w + 2 = 0

Use the discriminant to determine how many real-number solutions the equation has

A.2
B.1
C.0

4 answers

The discriminant is b^2-4ac. For the equation you posted, a=1 (the coefficient on w^2), b=-2, and c=2. Plug those numbers in. If the number you get is positive, there are 2 real number solutions. If you get zero, there is 1 solution. If you get a negative number, there are no solutions. Post your answer if you want it checked.
Actually, if you get a negative discriminant, you get no real solutions, but insteady, you get complex (in the imaginary domain) solutions, that in general, are valid.
eg. x^2+0x+1=0

the discriminate is sqrt(-4)

and in fact, then the solution is

x= +- i
Is the answer 0 not sure if this is correct.
Show me your work. You have to plug in the numbers.