Tuesday, August 28, 2018

10.3#7


Dr. Taylor, I have been racking my brain for 30 minutes on this problem, and I don't see any possible answer other than the one I have given. I used the projection formula we learned in class and even went through the problem with a fellow classmate who agreed that my work seemed correct. Thank you for your time.




















********************
well, you have the vector projection correct.  The scalar projection is b.a^  =  b.a/||a|| which is 
             [(-1)x3 + 4x(-3) + (-1)x(-4)]/√(3^2 + (-3)^2 + (-4)^2)  = [-11]/√34

So, your issue is you're using b.a/||a||^2 (and maybe also that you didn't look at the textbook?)