# Thread: Order of Operations with Trig Function

1. ## Order of Operations with Trig Function

I'm trying to make a table of values for the trigonometric function $\displaystyle y = 2sin3(x-30) +1$, though I don't know exactly how to punch this into my calculator (confused with the order of operations).

All I know is that from the parent function, $\displaystyle y = Sinx$, the following transformations have been made:

Phase angle shift: $\displaystyle 30deg$ right.
Amplitude: V.E. by $\displaystyle 2$. Therefore, $\displaystyle 2$.
Period: H.C. by $\displaystyle 3$. Therefore, $\displaystyle 120deg$.
Vertical shift: $\displaystyle 1$ up.

How would I solve for y if $\displaystyle x = 0deg$?

2. Do you mean $\displaystyle y=2\sin(3(x-30))+1$, or $\displaystyle y=2\sin(3)(x-30)+1$? Putting careful parentheses around all function arguments is a very good way to enhance clarity of expressions.

What kind of calculator do you have? If it's HP with the reverse Polish, let some other (poor) fellow help you out. If it's a more normal calculator, especially if it allows parentheses, you should be able to enter it more or less as it shows up on the page. Also, I would highly recommend you double-check to see if the calculator is in degrees or radian mode. I'm assuming the 30 is degrees?

3. That's the problem here, I don't know where the parenthesis are supposed to be; that's how much teacher typed it. My calculator is on degrees mode. And yes, the 30 is in degrees. I know how to use parenthesis in my calculator, I'm just unsure as to where the parenthesis belong. Is it possible that I can deduce the correct values with the transformations?

4. I'm guessing the first option I mentioned in Post #2 is the correct one. That is, $\displaystyle y=2\sin(3(x-30^{\circ}))+1$. Does that help? Are you still stuck?

5. Yes, problem solved! Thank you.

### content

Click on a term to search for related topics.