What is the period of f(theta) = tan ( (5 theta)/7) - cos ( (2 theta)/9) ?

1 Answer
Dec 14, 2016

63pi

Explanation:

Period of tan ((5t)/7) --> (7pi)/5
Period of cos ((2t)/9) --> (18pi)/2 = 9pi
Find least common multiple of (7pi)/5 and 9pi
(7pi)/5 ...x... (5)(9) ...--> 63pi
9pi ..... x ... (7) .... --> 63pi

Period of f(t) --> 63pi