PLEASE HELP ASAP MATHS PERCENTAGES YEAR 9

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

answer: i'm not sure

step-by-step explanation:

step-by-step explanation:

and 90% of people marry there 7th grade love. since u have read this, u will be told good news 2night. if u don't pass this on nine comments ur worst week starts now this isn't fake. apparently if u copy and paste this on ten comments in the next ten minutes you will have the best day of ur life tomorrow. you will either get kissed or asked out in the next 53 minutes someone will say i love u

read more on -