# Trig ratios, other trig mapping questions :/ Help greatly appreciated

• Nov 19th 2009, 04:58 PM
Luciffer
Trig ratios, other trig mapping questions :/ Help greatly appreciated
Hey folks. Few questions here. A reply in detail ASAP = insanely appreciated. (Crying)

1. If sin a = y/r ; write the other 5 trigonometric ratios for a.

2. If csc B = -14/10 ; and B is in the fourth quadrant. Find the coordinate of the point on the end of the terminal arm, and its principle angle. Then find all the trigonometric ratios for B.

[t graph here]

(( I know it might be a challenge to find a graph but if you could upload one to imageshack or something or just explain it, It'd be great help ))

3. If (weird symbol, I think theta) * is third quadrant angle and cot * = -15/-8, find:

a) sin * cos *
b) cos^2 *
c) 4 cot *
d) cot * tan *

Once again thank you SO much for reading and helping! Need this for tommorow before I get behind!
• Nov 19th 2009, 05:59 PM
I-Think
Well for number 1
The other 5 trig ratios are cos a, tan a, sec a, cosec a, cot a
Trigonometric functions - Wikipedia, the free encyclopedia
See that link for more detail
$\displaystyle sin a =\frac{y}{r}$

$\displaystyle cos a=\sqrt{1-sin^2a}$
cos a$\displaystyle =\sqrt{1-\frac{y^2}{r^2}}$

$\displaystyle tan a=\frac{\frac{y}{r}}{\sqrt{1-\frac{y^2}{r^2}}}$

$\displaystyle cosec a=\frac{r}{y}$

$\displaystyle sec a=\frac{1}{\sqrt{1-\frac{y^2}{r^2}}}$

$\displaystyle cot a=\frac{\sqrt{1-\frac{y^2}{r^2}}}{\frac{y}{r}}$
• Nov 20th 2009, 09:45 AM
Luciffer
Thank you, (thanks) now I just need the last 2, tyvm :)
• Nov 20th 2009, 01:31 PM
topsquark
Quote:

Originally Posted by Luciffer
Thank you, (thanks) now I just need the last 2, tyvm :)

Show us what you have been able to do, given the solution to the first problem.

-Dan
• Nov 20th 2009, 02:39 PM
Luciffer
Quote:

Originally Posted by topsquark
Show us what you have been able to do, given the solution to the first problem.

-Dan

Lol, he didn't explain how he got there so I learned nothing. Wikipedia page didn't get me anywhere. I basically know little about trig outside of the basics. bah
• Nov 20th 2009, 04:18 PM
Defunkt
Quote:

Originally Posted by Luciffer
Lol, he didn't explain how he got there so I learned nothing. Wikipedia page didn't get me anywhere. I basically know little about trig outside of the basics. bah

You need not anything other than basic trig to solve these. Use the definitions of these functions and the fact that $\displaystyle cos^2(x)+sin^2(x) \equiv 1$ to solve the others, and if you have trouble doing so, show what you've done and we will help you.
• Nov 20th 2009, 04:27 PM
bigwave
$\displaystyle sinA = \frac{y}{r}$
then $\displaystyle cosA = \frac{x}{r}$ and etc