# Is #f(x)=(12x^2-16x-12)/(x+2)# increasing or decreasing at #x=5#?

By signing up, you agree to our Terms of Service and Privacy Policy

To determine whether ( f(x) = \frac{{12x^2 - 16x - 12}}{{x + 2}} ) is increasing or decreasing at ( x = 5 ), we can evaluate the derivative of the function at that point.

First, find the derivative of ( f(x) ) using the quotient rule:

[ f'(x) = \frac{{(12x^2 - 16x - 12)'(x + 2) - (12x^2 - 16x - 12)(x + 2)'}}{{(x + 2)^2}} ]

[ f'(x) = \frac{{(24x - 16)(x + 2) - (12x^2 - 16x - 12)(1)}}{{(x + 2)^2}} ]

[ f'(x) = \frac{{24x^2 + 8x - 32x - 32 - 12x^2 + 16x + 12}}{{(x + 2)^2}} ]

[ f'(x) = \frac{{12x^2 - 16}}{{(x + 2)^2}} ]

Now, plug in ( x = 5 ) to determine whether the derivative is positive or negative:

[ f'(5) = \frac{{12(5)^2 - 16}}{{(5 + 2)^2}} ]

[ f'(5) = \frac{{12(25) - 16}}{{49}} ]

[ f'(5) = \frac{{288}}{{49}} ]

Since ( f'(5) > 0 ), ( f(x) ) is increasing at ( x = 5 ).

By signing up, you agree to our Terms of Service and Privacy Policy

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

- 98% accuracy study help
- Covers math, physics, chemistry, biology, and more
- Step-by-step, in-depth guides
- Readily available 24/7