[IB Math SL] Exam Review: Composite and Inverse Functions

[kai-fshl]

in the example of finding domain and range of 1/square root (9-x^2), at timestamp 5.40, you say the range is all real numbers except 0 however the result of the square root HAS to be positive therefore the dominator will be something positive therefore 1/a positive real number = a positive real number. so shouldn't the rage be all positive real numbers (excluding 0 and negatives)?

[drdark]

thank you you so much I have exam tomo about function I hope I will did well