I'm given f''(x) = sin(3x)ln(x+5) - xcos(3x)
1. List intervals where f(x) concave up & concave down with justification.
Normally you can find this by getting f''(x) = 0 right? But how do I take that function = 0?
I'm given f''(x) = sin(3x)ln(x+5) - xcos(3x)
1. List intervals where f(x) concave up & concave down with justification.
Normally you can find this by getting f''(x) = 0 right? But how do I take that function = 0?
Hello, mettler!
I've made a few observations . . . that's all.
I'm given: $\displaystyle f''(x) \:=\: \sin(3x)\ln(x+5) - x\cos(3x) $
1. List intervals where $\displaystyle f(x)$ is concave up & concave down with justification.
Normally you can find this by getting $\displaystyle f''(x) = 0$, right?
But how do I take that function = 0?
Note that the domain is $\displaystyle x > \text{-}5$
The equation cannot be solved by elementary means.
By inspection, we find that $\displaystyle x = 0$ is a solution.