Given u= <2,4>, and another vector v= 1,-1>, find proj(v) u?

Question

The v beside proj is supposed to be a subscript

Answer 1

The projection of v on u is Length v TIMES INNER PROD uv TIMES u



= sqr(2)((-2))<2, 4> = -2sqr(2)<2, 4>

Answer 2

The projection of u onto v is v*(u dot v)/||v| = -2/sqrt(2)*v = -sqrt(2)v

Answer 3

oh ya i remember doing this in differential equations



its not hard, just google the projection formula then plug and chug