How many solutions does the equation x^2 - 16x + 64 = 0 have?

2 Answers
Aug 19, 2016

Conventionally, we say that the eqn. has 2 identical roots : 8&8.

Explanation:

x^2-16x+64+0 rArr (x-8)^2=0

rArr x=8, &, x=8

Conventionally, we say that the eqn. has 2 identical roots : x=8,8.

Aug 20, 2016

For the quadratic equation ax^2+bx+c=0, the discriminant Delta=b^2-4ac tells us about the nature of the equation's roots:

  • If Delta>0, the equation has two real roots.
  • If Delta=0, the equation has a single double root.
  • If Delta<0, the equation has no real solutions.

So, for x^2-16x+64=0, we see that a=1, b=-16, and c=64. Thus:

Delta=b^2-4ac=(-16)^2-4(1)(64)=256-256=0

Since Delta=0, the equation has one single solution.