how do I find the range of f (x)= sqrt ((x^2)-2x-15) algebreicly

Question

It's pretty self exclamatory.                 .      .

Answer 1

The range of the square root of x^2 -2x-15 is (0, +infinity).  Range is the y component, listed from the smallest value to the greatest value. There is no real number negative y value for a square root.

Try Dx for domain and Ry for range to remember which one is x and which one is y.

 

Richard Moore, EIT, MRE

retired math and science teacher

Answer 2

The domain of this function is (-∞ , -3] ∪ [5 , ∞ )

At x = -3 or x =5  the argument of the sqrt is zero.   Thus the range is [0, ∞ )