The function $f(x)$ is defined only on domain $[-1,2]$, and is defined on this domain by the formula f(x) = 2x^2-8x+1. What is the range of $f(x)$? Express your answer as an interval or as a union of intervals.
2(-1)^2 -8 (-1) + 1 = 11
2(2)^2 - 8(2)+ 1 = -7
Range = [ -7, 11 ]