Help With Sine & Cosine Graphs - A Levels!!!

Guys Ive already completed these two quention sheets, just wanted to clarify thatthey are correct. Hmm I wonder how clever Sythe users are...


http://img545.imageshack.us/img545/74/22750384.png

http://img838.imageshack.us/img838/7268/untitl1ed.png


Thanks in advance!
I hope my answers match your's; Im only asking since this was my first
attempt at these series of questions. BTW I'm British student studying A-Levels;
Aged only 16.

 

You do realize it allows you to use your calculators? It's not that hard just remember the several basic identities

(sin x)^2 = sin^2x
tan x = sin x/cos x
sin^2x + cos^2x = 1
sin(a*+b*) = sina*cosb*+sinb*cosa*
* = degrees

There's a few others but it was so long since I've done then.

I'll just do the first one quickly of untitled image;
sinx = 3/8
cos^2x = 1 - sin^2x
= 1 - 9/64
= 55/64
cosx = (55^(1/2))/8

You can work the rest of it out from there but like I said, giving you the graphs and allowing you to use a calculator makes it fairly easy. And if you're as smart as you think you are then give me a help with matrices http://sythe.org/showthread.php?t=1042550

 

^ do not know what that guy is talking about.

this is simple graphing.

for example: sin x = 0.94

-> mark 0.94 on the y axis and find all corresponding x values on the wave (theres 4 of them obviously)

for cosine problems, shift the graph 90 degrees to the left and do the same.

 

or just punch it into your calculator for easy mode

 

It wont be accurate that way, that way of solving is for like grade 8 >.> and you cant just simply put sin x into your calculator... /facepalm

 

You're supposed to use your calculator to find the first answer, then using what I learned as "All Students Take Calculus," you can find the others.

 

the instructions for one of them say specifically to use the graph and rounding. the second worksheet you can just use inverse functions on your calculators. simple