Question

If the interval (a, oo) describes all values of x for which the graph of f(x) =

4
x2 - 6x +9
is decreasing, what is the value of
a?

Answer 1

Answer:

a = - 1.1

Explanation:

Condition for a single variable function f(x) to be decreasing is f'(x) < 0.

So, in our case, .

Then, differentiating with respect to x on both sides we get,

⇒

⇒

{Dividing both sides with - 1 and hence the inequality sign changes}

⇒

⇒ 8 > - 6x³ {Multiplying both sides with x³}

⇒ 6x³ > - 8 {Interchanging the sides}

⇒

⇒ x > - 1.1

Therefore, a = - 1.1. (Answer)

Explanation:

Answer 2

3

Explanation:

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