A parabola with equation y = x^2 + bx + c passes through the points (-1,-11) and (3,18). What is c?
+14995 A parabola with equation y = x^2 + bx + c passes through the points (-1,-11) and (3,18). What is c?
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\(y=x^2+bx+c\\ P_1(-1,-11)\\ P_2\ (3,18)\)
\(-11=1-b+c\\ 18=9+3b+c\\\)
\(c=-11-1+b=18-9-3b\\ 4b=18-9+1+11\)
\(b=5.25\)
\(c=18-9-3b\\ c=18-9-3\cdot 5.25\)
\(c=-6.75\)
The parabola has the equation \(y=x^2+5.25x-6.75\)
