At what points in history did most americans favor isolationist policies?

During the 1930s, the combination of the Great Depression and the memory of tragic losses in World War I contributed to pushing American public opinion and policy toward isolationism. Isolationists advocated non-involvement in European and Asian conflicts and non-entanglement in international politics. Although the United States took measures to avoid political and military conflicts across the oceans, it continued to expand economically and protect its interests in Latin America. The leaders of the isolationist movement drew upon history to bolster their position. In his Farewell Address, President George Washington had advocated non-involvement in European wars and politics. For much of the nineteenth century, the expanse of the Atlantic and Pacific Oceans had made it possible for the United States to enjoy a kind of “free security” and remain largely detached from Old World conflicts. During World War I, however, President Woodrow Wilson made a case for U.S. intervention in the conflict and a U.S. interest in maintaining a peaceful world order. Nevertheless, the American experience in that war served to bolster the arguments of isolationists; they argued that marginal U.S. interests in that conflict did not justify the number of U.S. casualties.

2.1% is the answer.

Answer:     the interval on which the curve is concave up is  (-∞, -1/2)======    we find the interval where this curve is concave up by finding the interval in which the 2nd derivative is positive.differentiate the curve equation with respect to x    let the function f denote be the anti-derivative of the inside expression, i.e. a function such that .then use the fundamental theorem of calculus:     differentiate again to get second derivative. we can use chain rule with 1/x as the outside function and 1 + x + x² as the inside function    find critical numbers of the second derivative. these numbers are where the 2nd deriv. is undefined or zero.where the 2nd derivative is zero: set (d²y/dx²) to equal 0 and solve for x    where the 2nd derivative is undefined: if the denominator is equal to zero, the derivative will be undefeined. attempting to solve the equation    1 + x + x² = 0results in a discriminant of      meaning that the equal 1 + x + x² = 0 has no real solutions and therefore will never equal zero.======our only critical number is x = -1/2.this forms two intervals to test the sign for: (-∞, -1/2) and (-1/2, ∞)test values into the 2nd derivative for (-∞, -1/2)if we try x = -1, we get      so the since the 2nd derivative of the curve is positive on the interval  (-∞, -1/2), the curve is concave up on (-∞, -1/2)test values into the 2nd derivative for (-1/2, ∞)if we try x = 0, we get      so the since the 2nd derivative of the curve is positive on the interval  (-∞, -1/2), the  curve is concave down on (-∞, -1/2).the interval on which the curve is concave up is  (-∞, -1/2)