Question

In which interval is the radical function f of x is equal to the square root of the quantity x squared plus 2 times x minus 15 end quantity increasing?
[3, ∞)
(4, ∞)
[–5, 3]
(–∞, –5] ∪ [3, ∞)

Answer 1

Using function concepts, it is found that it is increasing on the interval:

(–∞, –5] ∪ [3, ∞)

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The function is given by:

$f(x) = \sqrt{x^2 + 2x - 15}$

The graph is given at the end of this question.

• If the function is pointing upwards, it is increasing. Otherwise, it is decreasing.
• In the graph, it can be seen that it is pointing upwards for x of -5 and less, or 3 and higher, thus, the interval is:

(–∞, –5] ∪ [3, ∞)

A similar problem is given at brainly.com/question/13539822