General

[url=http://www.coolmath.com/precalculus-review-calculus-intro/index.html]This website helped me a ton when I took AP Calc last year.[/url]
Gives easy to approach/concise explanations on almost all topics about Pre-Calc.

Edit: Two things about that link:
1. I would skip the first 5~6 unless you need a refresher in Alg 1 and 2 also.
2. What's not on there that's crucial for Calc is polar coordinates iirc.

[quote=charismatic]Most professors I've worked for would give full credit if you left your answer as arcsin(2/5) since it's transcendental. So yes and no to the calculator thing.[/quote]

Actually, the exact form of the answer (left as "arcsin(2/5)&quot would be "most correct", as the calculator would just give you a decimal approximation of an irrational number.

@OP It is almost never necessary to solve for approximate decimal values. Just leave the solution in its exact form unless specifically instructed to do otherwise.

[quote=charismatic]@nopaycheck: I've written a solution with explanations and uploaded it [url=http://docs.google.com/open?id=0B6Ao9mFvL0TFUW9YOFlpZnJieHc]here[/url] for your reference. Please let me know if you have questions on this solution.

Good luck!

edit: I reuploaded it after fixing some typos. Please be sure to refresh the page if you were viewing this before.[/quote]

So you DID need a calculator to solve #1. I was trying to show work through non-calculator.
Wow, thanks a bunch!

^ Thats boss

[quote=nopaycheck]For #1, I get how sin x = 2/5, but how did that suddenly turn into 1/2 o-o
Also confused with the transition from step 2 to 3 in #2.[/quote]

EDIT: Perhaps not trolling attempt, but incorrect nonetheless. Nothing equals 1/2, or π/6 for that matter.

sin(x) = 2/5, so to solve for x you would do inverse sin (a.k.a. arcsin(x), sin^-1(x), Sin(x), etc.) on your calculator/slide rule.

[quote=nopaycheck]where's the arc sin button on a TI-84, LOL I turned into a pure idiot.[/quote]

2nd + sin.
arcsin, arccos, arctan is denoted as sin^-1, cos^-1, tan^-1 on your Ti84

:edit: got ninja-ed

btw if your Trig is as weak as I see it, you should either take trig again before Calc AB or seriously haul ass on reviewing that stuff.
Review Trig Identities, that is a MUST.

[quote=nopaycheck]where's the arc sin button on a TI-84, LOL I turned into a pure idiot.[/quote]

It should be an auxiliary function of the sin button, represented as sin -1, with the -1 being superscript. [2nd] [SIN] unless the layout has changed. I stopped using TI calculators years ago.

I hate that the school system indoctrinates students on TI calculators. HP48 series is infinitely superior, but no one knows or bothers to learn RPN. It makes me sad.

[quote=LEGENDairy]1.
5sinx = 2
sinx = 2/5 = 1/2
x = pi/6

2.
2sin(x + pi/3) = -1
sin(x + pi/3) = -1/2
x + pi/3 = -pi/6
x = -pi/2

3.
9^(2x-1) = 3^(2x+5)
(3^2)^(2x-1) = 3^(2x+5)
2(2x-1) = 2x+5
4x-2 = 2x+5
2x = 7
x = 7/2

Not 100% sure they're right.[/quote]
For #1, I get how sin x = 2/5, but how did that suddenly turn into 1/2 o-o
Also confused with the transition from step 2 to 3 in #2.

1.
5sinx = 2
sinx = 2/5 = 1/2
x = pi/6

2.
2sin(x + pi/3) = -1
sin(x + pi/3) = -1/2
x + pi/3 = -pi/6
x = -pi/2

3.
9^(2x-1) = 3^(2x+5)
(3^2)^(2x-1) = 3^(2x+5)
2(2x-1) = 2x+5
4x-2 = 2x+5
2x = 7
x = 7/2

Not 100% sure they're right.

[quote=rabbithole]For 1, you'll need arcsin to be able to get just x.

So sin x = 2/5
x = arc sin (2/5)

Whatever arc sin of 2/5 is in your calculator.[/quote]
where's the arc sin button on a TI-84, LOL I turned into a pure idiot.

i'm in your year and i started calc bc. tbh at this point in time i have actually no idea what's going on. hoping it'll click soon lol

For 1, you'll need arcsin to be able to get just x.

So sin x = 2/5
x = arc sin (2/5)

Whatever arc sin of 2/5 is in your calculator.

For 2, you need to use the multiple angle addition formula, which is sin(A+B) = sin A cos B + cos A sin B.

(sin x) (cos pi/3) + (cos x) (sin pi/3) = -1/2

cos pi/3 = 1/2 and sin pi/3 = (square root of 3)/2

(sin x)(1/2) + (cos x)(square root of 3 /2) = -1/2
(sin x) + (cos x)(square root of 3) = -1

[quote=2lazy2makeaname]1. & 2. just isolate x, youll have to use inverse trig to solve for x

3. remember logs or ln?[/quote]
I got #3 and I know i have to use the inverse trig functions for 1 & 2, but i forgot how =(

1. & 2. just isolate x, youll have to use inverse trig to solve for x

3. remember logs or ln?

lol taking calc as a jr... i have to take it as a SENIOR.