# Thread: need geometry help. Its all online so i have no help whatsoever.

1. ## need geometry help. Its all online so i have no help whatsoever.

Questions 14-16: Use the triangle to calculate the specified trigonometric values.

14.Ca
lculate sin
a. 7/ square root of 13
b. 6/ square root of 13
c. 6/ square root of 85
d. 7/ square root of 85

15.Calculate cos
a. 7/ square root of 13
b. 6/ square root of 13
c. 6/ square root of 85
d. 7/ square root of 85

16.Calculate tan
a. 7/ square root of 13
b. 6/ square root of 13
c. 6/ square root of 85
d. 7/ square root of 85

17. If tan=5/4 calculate the value of cos

a. 5/ square root of 41
b. 4/ square root of 41
c. 5/3
d. 4/3

18. If cos= 2xsquare root of 10/7 calculate the value of sin.

a. 3/7
b. square root of 29/7
c. square root of 69/7
d. square root of 89/7

19. If sin= 1/ square root of 2 find the value of 0.

a. 30º
b. 45º
c. 60º
d. 90º

Questions 20-22: Use a calculator to find the trigonometric value to four decimal places.

20. cos 88º =
a. 0.0354
b. 0.0114
c. 0.9994
d. 0.0349

21. sin 47º =
a. 0.7314
b. 0.6820
c. 0.1236
d. 1.0734

22. tan 8º =
a. 6.7997
b. 0.1405
c. 0.1392
d. 5.6713

2. ## Re: need geometry help. Its all online so i have no help whatsoever.

For 14-19, you need an "argument" for your sin, cos, tan functions. For example, $\displaystyle \cos$ means nothing but $\displaystyle \cos \theta$ or $\displaystyle \cos 88^{\circ}$ mean something. How do we know you're not asking for $\displaystyle \sin 2 \theta$?

Also, for the right triangle, $\displaystyle \sin \theta = \frac{opp}{hyp}$, $\displaystyle \cos \theta = \frac{adj}{hyp}$, and $\displaystyle \tan \theta = \frac{\sin{\theta}}{\cos{\theta}} = \frac{opp}{adj}$, where opp and adj are the sides opposite to and adjacent to $\displaystyle \theta$. By the Pythagorean theorem, the hypotenuse is $\displaystyle \sqrt{7^2 + 6^2} = \sqrt{85}$.

For 20-22, use your calculator. Or Wolfram Alpha/Mathematica (make sure you are in degree mode). We can help you with your math problems, but ultimately you're the one that's supposed to do the work and submit your answers/solutions.

3. ## Re: need geometry help. Its all online so i have no help whatsoever.

14-16 have a slashed zero after the cos,tan, and sin

4. ## Re: need geometry help. Its all online so i have no help whatsoever.

That's the Greek letter theta.