Trig IDs and Equations

This section was initially really hard to learn. The sum and difference IDs could be really tricky. However, by the time the test came around I really understood the material. I liked that it went with the unit circle because unit circle makes sense to me. Graphing was a little difficult though.

3. sin2x= 2sinxcosx
    2(12/13)(5/13)
    120/169

5. x= -348.32 and -16.32 and 11.68 and 191.68

Simple Harmonic Motion

I really liked this unit. It was easy to understand and- dare I say it- fun to do. It made sense and I liked that it was applicable to the real world.

1b. Amp: 3.5 feet
      period: 24 hours
      phase shift: none
      vertical shift: 4.5 feet

2c. Feb 13th: 27/28 months
      y= -25.9cos30(.97-1)+59.1= 33.2

Inverse Trig

I don't really know why I only got an 82 when I understood this unit so well. Well, I do know; I messed.up the domain and range a lot. Other than that, I did pretty well and understood it.

2c. tan(arccos 3/5) = 4/3 or -4/3

2b. Arccos(sin pi/2) = Arccos1 = 0 and 180

Midterm Reflection

1. If I'm being perfectly honest, I did not do much studying. I forgot to do the vocab and did no outside of school work. The only real way I studied was by scanning the material 10 minutes before class.

2. I don't think there's anything I'd do differently. The only thing I would do differently is I'd remember to do the vocab.

3. It was not difficult. I got a 92, and that wasn't too hard, as evidenced by my clear lack of preparation.

17. Arctan -1 = 7pi/4

18. tan(Arcsin 1/2) = tan pi/6 = (square root of 3)/3

25. sinB = y/r     tanB = y/x
       x=r at 0 and pi
      sin 0 or tan 0= 0 + 360k where k is an integer

Graphs of Trig Functions

I overall like this unit because it reminded me of easier units in Algebra II. I could view it as graphing any other function, except this was trigonometry. I did not find it to be exceptionally difficult and only made dumb mistakes on the test.

2.b. range: all values of x where x is a real number, except pi/2 +/- kpi where k is an integer
       domain: all values of y where y is a real number

1. I got most of this right except what A means. A is the amplitude of the graph, which is the total vertical distance it spans divided by two, otherwise known as the size of the cosine waves

Trig Triangles

Overall, I thought this unit was pretty easy to do. It all made sense to me, with the exception of one type of problem where there were two triangles. I enjoy the trig units because the basic rules all apply.

3c. I solved for one triangle already, here is the other.
   180-88.1= 91.9 degree angle A
   sin33/14=sin91.9/a side a=25.69
   180- 91.9- 33= angle B= 55.1 degrees

Trigonometry and Unit Circles Test Corrections

I found the concepts in this unit to be relatively easy, with the exception of the one displayed in problem 4. I struggled, however, when it came to memorizing the unit circle. I knew the positives and negatives, but not the exact numbers, which hurt me on question 9.

4.
tan50.57= y/x
x= y/tan50.57
tan70.42=(y+3500)/x
x=(y+3500)/tan70.42
y/tan50.57= (y+3500)/tan70.42
y(tan70.42)= (y+3500)(tan50.57)
y(tan70.42)= y(tan50.57) +4256.42
2.81y= 1.22y +4256.42
1.59y= 4256.42
y=2676.99
+3500
6176.99 feet

8.
secx= -5/3
cos x= -3/5
hypotenuse: 5
adjacent: -3
opposite: -4
sin= -45
tan: 4/3