Answer with Step-by-step explanation:
We are given that

when x<9
when 
LHD

=
RHD



Hence, the function is not differentiable at x=9
Answer:
A. 4
Step-by-step explanation:
1. Use the SLOPE FORMULA: M= rise/run= y2-y1/x2-x1
2. Plug in the two coordinates that were plotted on the equation: (1,1) & (3,9)
3. Label the coordinates
( 1 , 1 ) = ( x1, y1 )& ( 3, 9 ) = ( x2, y2 )
4. SOLVE & PLUG IN
m = 9 - 1 / 3 - 1 = 8 / 2
5. Simplify 8/2 (Divide by 2)
6. answer: 4/1 = 4
Let's assume the frequency of sound be f and wave length is w.
Given that, the frequency of sound varies inversely as the wavelength.
So, we can set up an equation as following:
f*w = k Where k= constant of variation.
Other information is, the frequency of a musical note is 276 cycles per second when the wavelength is 1.2m.
So, next step is to plug in f = 276 and w = 1.2 in the above equation to get the value of k.
276 * 1.2 = k
So, k = 331.2
Next step is to plug in k = 331.2 in the above equation. So,
f * w = 331.2
Now we need to find the wave length : w when frequency : f = 600.
Therefore,
600 * w = 331.2

So, w = 0.552
Hence, the wave length is 0.552 m.
Hope this helps you!.
An acute angle is infact 90 degrees, therefore your answer is correct.