Answer:
Quality rotation is the act of a joint moving through a range of motion in a way that is efficient, controlled and repeatable.
]Eigenvectors are found by the equation

implying that

. We then can write:
And:
Gives us the characteristic polynomial:

So, solving for each eigenvector subspace:
![\left [ \begin{array}{cc} 4 & 2 \\ 5 & 1 \end{array} \right ] \left [ \begin{array}{c} x \\ y \end{array} \right ] = \left [ \begin{array}{c} -x \\ -y \end{array} \right ]](https://tex.z-dn.net/?f=%5Cleft%20%5B%20%5Cbegin%7Barray%7D%7Bcc%7D%204%20%26%202%20%5C%5C%205%20%26%201%20%5Cend%7Barray%7D%20%5Cright%20%5D%20%5Cleft%20%5B%20%5Cbegin%7Barray%7D%7Bc%7D%20x%20%5C%5C%20y%20%5Cend%7Barray%7D%20%5Cright%20%5D%20%3D%20%5Cleft%20%5B%20%5Cbegin%7Barray%7D%7Bc%7D%20-x%20%5C%5C%20-y%20%5Cend%7Barray%7D%20%5Cright%20%5D%20)
Gives us the system of equations:
Producing the subspace along the line

We can see then that 3 is the answer.
Click random buttons until you figure it out, or even ask a parent or teacher
Answer:
.
Step-by-step explanation:
The given function is

Using chain rule differentiate w.r.t. x.
![\left[\because \dfrac{d}{dx}\sin x=\cos x\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbecause%20%5Cdfrac%7Bd%7D%7Bdx%7D%5Csin%20x%3D%5Ccos%20x%5Cright%5D)
![f'(x)=\cos(9\ln (x))\left[9\dfrac{d}{dx}(\ln (x))\right]](https://tex.z-dn.net/?f=f%27%28x%29%3D%5Ccos%289%5Cln%20%28x%29%29%5Cleft%5B9%5Cdfrac%7Bd%7D%7Bdx%7D%28%5Cln%20%28x%29%29%5Cright%5D)
![\left[\because \dfrac{d}{dx}\ln x=\dfrac{1}{x}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbecause%20%5Cdfrac%7Bd%7D%7Bdx%7D%5Cln%20x%3D%5Cdfrac%7B1%7D%7Bx%7D%5Cright%5D)

Therefore,
.