Hello Stef,
Check the syntax here : https://docs.moodle.org/39/en/Simple_calculated_question_type#Correct_answer_formula_syntax.
" A notable exception is exponentiation, where x³ cannot be entered as {x}^3, but instead should be entered as pow(x, 3). "
Check the syntax here : https://docs.moodle.org/39/en/Simple_calculated_question_type#Correct_answer_formula_syntax.
" A notable exception is exponentiation, where x³ cannot be entered as {x}^3, but instead should be entered as pow(x, 3). "