I have my final tomorrow and I have a few questions and one that I have absolutely no idea about.
It says:
cos(x)= -3/8 90<x<180 compute sin(x + 78 pi)
I know to draw a triangle and find sin of x, but this whole 78 pi thing has me really confused.
The next thing is intervals. I have made it through the whole semester without understanding them. For example the question reads:
solve sin(5x)=1
on the interval [0, 2pi /5]
The answer is pi/10, but I only got that right from a guess.
Or here is another example,
sec^2(x)=1
over the interval [-pi/2, 5pi/2]
That answer is 0, pi, and 2pi,
but what does that interval stuff mean? Iv asked the teacher and tutors, but no one can explain it to me.
It says:
cos(x)= -3/8 90<x<180 compute sin(x + 78 pi)
I know to draw a triangle and find sin of x, but this whole 78 pi thing has me really confused.
The next thing is intervals. I have made it through the whole semester without understanding them. For example the question reads:
solve sin(5x)=1
on the interval [0, 2pi /5]
The answer is pi/10, but I only got that right from a guess.
Or here is another example,
sec^2(x)=1
over the interval [-pi/2, 5pi/2]
That answer is 0, pi, and 2pi,
but what does that interval stuff mean? Iv asked the teacher and tutors, but no one can explain it to me.