Vieta’s formulas have many applications in the general mathematics program in Vietnam. Indeed, they appear in many forms of mathematical problems, ranging from 9th, 10th and 12th grades. The complexity of the mathematical problems makes students commit many errors when using the Vieta’s formulas to solve them. The sample consisted of 246 students in grades 10 and 12, in which they addressed four questionnaires related to Vieta’s formulas. The results were quite unexpected because the errors of tenth graders also existed for 12th grade students for many different reasons. Article visualizations
