Combine like terms. Is there a picture for this?
When you see the subtraction<span> (</span>minus<span>) sign followed by a </span>negative<span> sign, turn the two signs into a plus sign. Thus, instead of </span>subtracting<span> a </span>negative<span>, you're adding a </span>positive<span>, so you have a simple addition problem.</span>
Answer:
sinΘ = 
Step-by-step explanation:
sinΘ =
=
= 

It's clear that for x not equal to 4 this function is continuous. So the only question is what happens at 4.
<span>A function, f, is continuous at x = 4 if
</span><span>

</span><span>In notation we write respectively
</span>

Now the second of these is easy, because for x > 4, f(x) = cx + 20. Hence limit as x --> 4+ (i.e., from above, from the right) of f(x) is just <span>4c + 20.
</span>
On the other hand, for x < 4, f(x) = x^2 - c^2. Hence

Thus these two limits, the one from above and below are equal if and only if
4c + 20 = 16 - c²<span>
Or in other words, the limit as x --> 4 of f(x) exists if and only if
4c + 20 = 16 - c</span>²

That is to say, if c = -2, f(x) is continuous at x = 4.
Because f is continuous for all over values of x, it now follows that f is continuous for all real nubmers 