Alright since my first question got deleted, I'd figured I tried to explain what I'm stuck with.

I have a sine wave that is down below.
Write an equation for the sine wave. What is the amplitude and period?
Now, you are going to determine the frequency of the tone you created.
The frequency formula is: frequency = 1/period

My exact points maybe off, mainly from my own confusion of this graph
Max Point: (-3, 2.5) (12, 2.5)
Min. Point: (4, -2.5)
Midline: y=0
Amplitude= 2.5
Period= 2π/-0.4 = -16
My equation: f(x)=2.5sin(-0.4(x-0.5))
frequency = 1/-16 (-0.0625 hertz? Or 1/-16 hertz)

I don't know if I'm completely off or on the right track, and would just like someone help me explain this a little more.
Thx!!

(4, -2.5)

Step-by-step explanation:

the value of v.w= -12.

step-by-step explanation:

we are given three vector r,v and w as:

r = < 5, -5, -2> ; v = < 2, -8, -8> ; w = < -2, 6, -5>

we know that r,v and w could also be represented as:

r=5i-5j-2k

v=2i-8j-8k

and w= -2i+6j-5k

where i,j and k are the unit vectors of x,y and z-axis respectively.

also we know that it has the following property:

i.i=1 ; j.j=1; k.k=1

and i.=j.i=i.k=k.i=j.k=k.j=0

i.e. when we multiply two vectors or we find it's dot product we need to only multiply the components of x coordinates with each other; y with each other and z with each other.

hence, v.w= (2i-8j- -2i+6j-5k)

                  = 2×(-2)+(-8)×(6)+(-8)×(-5)

                  = -4-48+40

                  = -12

hence, v.w= -12