let is perpendicular to < 1, -5, 2 >
Their dot product is zero
a - 5b + 2c = 0
=> a = 5b - 2c
there are many solutions
for example, let c = b = 1, a = 3 ==> < 3, 1, 1 >
Their dot product is zero
a - 5b + 2c = 0
=> a = 5b - 2c
there are many solutions
for example, let c = b = 1, a = 3 ==> < 3, 1, 1 >