For what value of c will this function have one zero?

f (x) = X^2 + c

X² + c is actually a quadratic function.

And x² + c = 0, it usually has two zeros which are solutions.

But for when c = 0,

x² + c = 0

x² + 0 = 0

x² = 0

Taking the square root of both sides.

x = 0. Here it only has one zero.

So the function x² + c, only has one root for c = 0.