Write the summation to estimate the area under the curve y = 1 + x^2 from x = –1 to x = 2 using 3 rectangles and right endpoints. the summation from i equals negative 1 to 2 of the quantity i squared plus 1 the summation from i equals 0 to 2 of the quantity i squared plus 1 the summation from i equals 1 to 3 of the quantity i squared plus 1 none of these