Evaluate:
$$\dfrac{\csc(90+\theta)+\cot(450+\theta)}{\csc(450-\theta)-\tan(180+\theta)}+\dfrac{\tan(180+\theta)+\sec(180-\theta)}{\tan(360-\theta)-\sec(-\theta)}$$
I simplified this into $$\dfrac{\sec(\theta)-\tan(\theta)}{\sec(\theta)-\tan(\theta)}+\dfrac{\tan(\theta)-\sec(\theta)}{-\tan(\theta)-\sec(\theta)}$$ $$1+\dfrac{\sec(\theta)-\tan(\theta)}{\sec(\theta)+\tan(\theta)}$$ $$1+\dfrac{\sec^2\theta+\tan^2\theta-2\sec\theta\tan\theta}{\sec^2\theta-\tan^2\theta}$$
Unfortunately I've got stuck here and cannot understand what to do. I'm not even sure if what I've done is correct; I was told that by the third step, the questions should be over.$$$$I would be truly grateful if somebody would kindly help me through solving this problem and also point out my errors. Many thanks in advance!