Posted by Anonymous on Saturday, March 29, 2008 at 7:18pm.
4*-1 + 1*4 = 0
cos angle = 0, so angle is 90 or -90 (240)
remember algebra 1
y = m x + b
the slope of a line perpendicular to that is -1/m
here we have a slope of 1/4
and the other slope is 4/-1
sure enough, perpendicular
7*4 + 8*-7
7*(4-8)= -28
|A|*|B|* cos angle = -28
sqrt(49+64)*sqrt(16+49)* cos angle = -28
10.6 * 8.06 *cos angle = -28
cos angle = -.328
angle = 109 deg
Related Questions
Math - Product Dot Vectors - How would you expand and simplify the following ...
math - given that vectors(p+2q) and (5p-4q) are orthogonal,if vectors p and q ...
Calculus - Two force vectors act on an object and the dot product of the two ...
PHYSICS VECTORS - 1. The problem statement, all variables and given/known data ...
Math - Vectors - If "u = (2,2,-1)", "v = (3,-1,0)" and "...
Calculus - For which following condition, will the dot product of two vectors be...
Physics (vectors) - Given vectors A= (Axi + Ayj), B= (Byj+Bzk) and C= (Cyj + Czk...
calculus - Find two unit vectors that make an angle of 60° with v = ‹3...
math - given that vectors(p+2q) and (5p-4q) are orthogonal,if vectors p and q ...
Vectors - If vector a and b are unit vectors, and |a+b|= root3, determine (2a-5b...
For Further Reading
