Saturday

February 28, 2015

February 28, 2015

Posted by **Piper** on Tuesday, February 3, 2009 at 4:27pm.

Work:

P= (-15/17, -8/17)

cosΘ = a value

P = (a,b)

sinΘ = b value

Answer:

cosΘ = -15/17

sinΘ = -8/17

2. Should the triangle be solved beginning with Law of Sines or Law of Cosines. THen solve the triangle and found to the nearest tenth. a = 16, b = 13, c = 10.

Work:

c^2 = a^2 + b^2 -2abcosC

100-16^2+13^2-2*16*13cosC

100= 256+169 -416cosC

100=425-416cosC

-325=-416cosC

.78125=cosC

Answer: 38.6°, Law of Cosines is used

3. Should the triangle be solved beginning with Law of Sines or Law of Cosines. Then solve the triangle and round to the nearest tenth. A = 56 degrees, B = 38 degrees, a = 13.

Work:

SinA/a = SinB/b

sin56/13= sin38/b

Answer: 9.7

3. Find the exact value of tan(-3pi)

Work: tan(-3pi) = tan(-3pi+2pi) = tan (-pi) = tan (-pi+2pi) = tan (pi) = sin(pi)/cos(pi) = (0)/(-1) = 0

Answer : 0

- Trig - check my answers plz! -
**bobpursley**, Tuesday, February 3, 2009 at 4:47pmcorrect.

- Trig - check my answers plz! -
**vee**, Friday, December 26, 2014 at 5:03pmsimplify the expression tan 20 degrees +tan 25 degrees/ 1-tan 20 degrees tan 25 degrees

**Answer this Question**

**Related Questions**

please - Given tan Θ = - 8/5 and sin Θ < 0, find sin Θ, cos &#...

math-Trig - 1. Write the algebraic expression which shows Cos((ArcSin(4/X)), 2...

Math-Trig - Trig Questions- 1. Write the algebraic expression which shows Cos((...

Trig - Identies/equation, please help! - 2Sin(Θ+47°)=1 ΘЄ[0°, ...

Trigonometry - 1. Find the exact value of the following (Think identity) Cos(2 ...

TRIGONOMETRY HELP - Prove that: cosēΘ - sinēΘ = 2cosēΘ - 1

math - Solve the following equations giving any roots in terms of pi in the...

TRIGONOMETRY HELP - Prove that: (tanēΘ)x(sinēΘ) = (tanēΘ)-(sinē&#...

Pre-Calc - Let cis Θ = cos Θ + i sin Θ. Let z1 = 3 cis 25 and let...

Math - Let cis Θ = cos Θ + i sin Θ. Let z1 = 3 cis 25 and let z2...