Look past notation and efficiency in the responses. Which two use the same mathematical reasoning? Task: Differentiate h(x) = x² sin(x). Two responses may share the same product-rule error. Student 1: Use h'(x) = 2x sin x + x² cos x. Student 2: Write h'(x) = (2x)(cos x), multiplying the derivatives of the two factors. Student 3: Treat sin(x) as a constant and write h'(x) = 2x sin x. Student 4: Differentiate each factor separately and multiply the results together.