trigonometry

He said after realising he had seen an exam question, instead of alerting the exam board, he deleted the image containing the trigonometry question.

“You were never going to teach a first grader a trigonometry lesson, right?” she said.

Functions and trigonometry came easily, but the basics gave him trouble.

"I have lost count of the number of people who say they wish they had learnt about mortgages rather than trigonometry," she said.

Two high school students have proved the Pythagorean theorem in a way that one early 20th-century mathematician thought was impossible: using trigonometry.