Yay,blogs.

This week I’m going to talk about section 8-1. I’m also going to include the last few notes from 7-6 because those are important in this section as well. The trig chart is also useful.

To solve for Ɵ, the steps are going to differ from those of an algebra equation.

1. Isolate the trig function.

2. Take the inverse of said trig function.

*An inverse finds an angle by the way. Thought I’d let you know since I got that wrong on not only my multiple choice test, but also free response.

3. Use trig chart (she wasn’t lying about that thing being used for everything) or calculator to find answer. (only use positive value)

4. Use the quadrants to find the right angle. (positive or negative with trig function)

There are at least two answers for each inverse.

To move quadrants,

Q1-Q2 make negative and add 180°

Q1-Q3 add 180°

Q1-Q4 make negative and add 360°

You will also need to know the following:

m=tanx where m is the slope α “alpha” AKA “angle of inclination” of a line.

Tan2α=b/a-c finds the angle of inclination of a CONIC.

Ax^2+bxy+cy^2+…..=

EXAMPLE:

3cosƟ=1

First, divide by 3.

CosƟ=1/3

Next, take the inverse.

Ɵ=cos^-1(1/3)

Plug this into your calculator and set up this graph:

*note that you are searching for two positive angles.

Remember you switch from Q1-Q4 by making 70.529 negative and adding 360°.

From here you must convert to degrees minutes and seconds. Your final answer should be

Ɵ=70°31’44”

289°28’15”

And that’s how you do that. Also, Microsoft Word hates me therefore the random highlight and change of font that refuses to be changed.

--Sarah