Completing any assignment at home can be more involved a process that doing one in class. One major reason for this is that generally time will have passed since the concept was first explained to you and your understanding of it may have degrades slightly as a result. Here are some methods you can use to get help in times like that when your chosen subject is mathematics or specifically calculus:
There are many educational content providers online. The course providers are emerging as some of the more powerful players in the industry. Their services are of high quality and generally offered for free. Find one that is short and has a heavy calculus component and you will be able to gain useful advice and techniques that can make your homework simpler to complete.
Good text books become open source on a daily basis. There are also many writers who dedicate themselves to creating books that were never meant to be sold in the first place. Search for these and you will come across quite a few because mathematics has been a subject that has been studied deeply for many centuries.
Study groups can also attempt homework together. As more people work on a given assignment the time it takes to complete it will reduce significantly. There will also be a noticeable increase in the level of understanding shown by all members if they pay attention and give as much as they take.
This may be one of the less conventional methods you will find bu tit has been proven that information is more easily absorbed in entertaining ways. If you find a game that can teach you the basic rules of calculus and allow you to apply them regularly you will find your homework becoming increasingly simple each time you attempt it.
If your homework was taken straight from the required text you may be able to find answers this way. This should not encourage you to cheat or look for shortcuts. It is merely a way you can double check that your own answers are correct without involving others in the process.
Mathematical thinking grows more like second nature with each use so never forget to practice frequently.