Question

solve it for 50 points

class 11th physics


a=2i-3j+7k & b=-4i + 2j-4k. find the dot product a.b. of these two vectors if they are separated by q=60.​

Answer 1

Answer:

a=2i+3j+7k and b= -4i+2j-4k

a.b= |a| |b| cosФ

a.b= (i1) (i2) + (j1) (j2) + (k1) (k2)

a.b= [ 2*(-4) ] + [3*2] + [7* (-4)]

a.b= -8 + 6 - 28

a.b= -2 - 28

a.b= -30

Hope this answer will satisfy you...

Explanation:

Answer 2

Explanation:

a.b= |a| |b| cosФ

a.b= (i1) (i2) + (j1) (j2) + (k1) (k2)

a.b= [ 2*(-4) ] + [3*2] + [7* (-4)]

a.b= -8 + 6 - 28

a.b= -2 - 28

a.b= -30