Basic integral question & sin, tan, cos.

I've just been looking at some algebra called intergrals.

I understand this fully but in the next step when he simplifies it a little he turns the into

I don't understand why he put a 1 there in place of the . Where did the 1 come from? Also one other question I have which I have is:

I have a basic understand of sin, cos and tan but what exactly do the represent when used in equations?

Can someone just explain what these equation actually means? Thanks

Re: Basic integral question & sin, tan, cos.

If you look at the graph of (choose any ) and then simultaneously plot the graph of you will see that the second graph represents the instantaneous rate of change of the first.

Re: Basic integral question & sin, tan, cos.

But that's just it, what is -cos, cos, tan, sin etc? Are they actual constants like PI=3.14 etc? Would you be able to plot a graph just so I can see what value -cos represents.

Re: Basic integral question & sin, tan, cos.

I've just been looking at a cheat chart and I think something like the would represent ?

Re: Basic integral question & sin, tan, cos.

I'm sorry, you stated you have a basic understanding of the trigonometric functions, so I naturally assumed that you did.

There are many sites online that will graph functions, and to essentially teach trigonometry is beyond the scope for me in online posts. There is a great deal of online material though that can get you started. Just do a search on trigonometry.

I highly recommend you learn this before exploring the calculus!

Re: Basic integral question & sin, tan, cos.

Oh ok no problem, I thought this was still algebra, I must have been getting a bit carried away :D

Re: Basic integral question & sin, tan, cos.

I would recommend checking out Khan Academy there are videos that you can watch for trigonometry and also practice problems for this topic.