Q.762 Simply the sum
$$ \sec(\theta) + \sec(\theta)\sec(2\theta)+ \sec(2\theta)\sec(3\theta) + \cdots + \sec((n-1)\theta)\sec(n\theta) $$
Q.762 Simply the sum
$$ \sec(\theta) + \sec(\theta)\sec(2\theta)+ \sec(2\theta)\sec(3\theta) + \cdots + \sec((n-1)\theta)\sec(n\theta) $$