1. ## question about homework on convexity

http://www.math.ualberta.ca/~xichen/...05w/hw2sol.pdf

can someone tell me why in solution to #9, we can choose the scalars alpha and beta to be such that alpha + beta =1 ?

2. Originally Posted by squarerootof2
http://www.math.ualberta.ca/~xichen/...05w/hw2sol.pdf

can someone tell me why in solution to #9, we can choose the scalars alpha and beta to be such that alpha + beta =1 ?
For the point $u=\alpha p+ \beta q$ to lie in the interval $[p,q]$ you need $\alpha+\beta=1$ (for higher dimensions read line segment rather than interval)

RonL