Suppose that f(x)=3x−6x+5.

Use interval notation to indicate where f(x) is concave up or down.
Concave up:
Concave down:

Question

Suppose that f(x)=3x−6x+5.

Use interval notation to indicate where f(x) is concave up or down. 
Concave up:  
Concave down:

hunus · Answer

Is that supposed to be$$f(x)=3x^2-6x+5$$

anonymous · Answer

Oops! It's suppose to be 3x-6/x+5. Sorry and thanks!

hunus · Answer

$$f(x)=3x−6/x+5$$ $$f'(x)=3+6/x^2$$ $$f''(x)=-12/x^3$$ $$-12/x^3>0$$ $$-1/x^3>0 $$ when x<0 $$-12/x^3<0$$ when x>0 $$f(x)=3x−6/x+5$$ is concave up on the interval $$(-\infty, 0)$$ and is concave down on the interval $$(0, \infty)$$

anonymous · Answer

My online homework said this answer was incorrect :/

hunus · Answer

:( Are you sure all the information you gave me was correct?

anonymous · Answer

Uhm Yes, I just checked it again...