I need help please help me I don’t understand

Write a recursive sequence that represents the sequence defined by the following explicit formula:

Acourgette seed and a pumpkin seed is planted p(courgette seed germinates) 4/5 and p(pumpkin seed germinates) = 1/6 what is the probability that both seds germinate

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)