v= -2i - 3j
w= i - j
2007-08-20 06:20:00 · 4 answers · asked by jessie0420 2 in Science & Mathematics ➔ Mathematics
first u should know that
i.i =1
i.j=0
to solve this v.w=( -2i - 3j).(i - j)
-2+0+0+3=1
i multiple the first element in v with the two elements in w
then i multiple the second elements in v with the two elements in w.
i hope this help
2007-08-20 07:51:30 · answer #1 · answered by Khalidxp 3 · 0⤊ 2⤋
The dot product between two vectors X=(x1,x2) and Y=(y1,y2) is given by x1*y1+x2*y2.
So in this case v*w=-2*1+(-3*(-1))=-2+3=1
2007-08-20 06:28:21 · answer #2 · answered by Anonymous · 0⤊ 0⤋
the answer's 1
all u haf to do is : multiply the corresponding coefficients of 'i' & 'j' vectors and add the products
2007-08-20 06:32:45 · answer #3 · answered by Gauri 1 · 0⤊ 0⤋
(-2i - 3j) . (i - j) = - 2 + 3 = 1
2007-08-20 07:41:27 · answer #4 · answered by Como 7 · 3⤊ 0⤋