Tat says he found out two weeks after school started in July that he would have to pay to take the class at North Carolina State University. Only three students signed up, which was not enough to meet the minimum enrollment requirement to have the class taught on campus.
In the past, Tat, who is a senior at Southeast, says the school's former principal picked up the $550 tuition bill.
"Since 2002, our previous principal, John Modest -- he's been paying for our course," Tat said.
Tat expected Beulah Wright, the school's new principal, to follow that tradition, but she is not.
Wright declined to talk with WRAL and referred all questions to the Wake County School Central Office instead.
A school system spokesperson told WRAL that Wright is following school system policy, adding that it is too expensive to pay for every student who wants to take college level courses.
Tat says he feels the school system is missing the point. Southeast is a technology magnet school with a focus in math and science. He feels these courses are vital to the school's reputation.
"We're trying to recruit advanced students," Tat said. "How's that going to affect our school?"
Tat and other students can take the class at nearby Enloe High School. But because Southeast follows a modified year-round schedule and Enloe is on a different calendar, Tat says taking the class would conflict with other classes he is trying to take at Southeast.
Tat's mother paid the bill so Tat could take the calculus class at N.C. State. Still, he says he is not giving up hope that he can convince the school system to reconsider picking up the bill.