the relative minimum of the function sqrt(a^2+x^2)

i usually know how to solve but the a is throwing me off a little bit.........the answer options are

no relative minimum

x = 0

x = a

x = a^2

Question

the relative minimum of the function sqrt(a^2+x^2)

i usually know how to solve but the a is throwing me off a little bit.........the answer options are 
		
no relative minimum
		
x = 0
		
x = a
		
x = a^2

anonymous · Answer

$x^2$ is always positive, except if $x=0$ so that will give you the minimum

anonymous · Answer

thx so much :) sometimes i forget that i dont actually have to solve the problem and i can just use logic :P