Question 701800
Graph the portion of the function which is in the domain between -1 and 5, inclusive; ALL of the function in that domain.

{{{graph( 300, 300, -1, 5.1, -4, 42, 2x^2-x-3 )}}}


The righthand endpoint is (5, 42), and the lefthand endpoint is (-1, 0).  You made some mistake in computing your point of (-1, -2).
See, {{{2*(-1)^2-(-1)-3=2+1-3=0}}}