Actually the answer is Area is non zero and finite because Area can never be zero but integration can be zero.(The difference as i have read in a prev gate question is that Area we take the positive summation only but for integration the summation can be -ve or +ve ( like in graph of x3 over -1 to 1 etc) ) .Hence, i said yes because he didn't ask for the actual sum.Coming to the actual sum, sqrt(x) is not defined from -1 to 0 hence unless we use complex values.But yes, if u use complex number then as you said the answer is coming 2(1-i).