Question

Find range: f(x)=root[9-x^2].ans is [0, 3], but how?domain is [-3, 3], so can't we put 0 in the equation and get plus minus 3 and the range become [-3, 3]?root[9-0^2]=root[9]=plus minus 3

Answer 1

y=√9-x^2
⇒x=√9-y^2
Range of y=domain of x= (0,3)
here roots means positive root only as per convention