Posted by jeff on Sunday, May 16, 2010 at 9:14am.
I am taking an online class, and cant understand why when I calculate ona ti84 plus an answer I get decimal answer and my teachers answer is sq root, is there something I am not doing on my calculator? How do I convert.
Example, teachers answer to the following was
sin 315deg = -sin 45deg = -sqrt2/2
I got a decimal answer.
- algebra 2 - Reiny, Sunday, May 16, 2010 at 10:51am
You should become familiar with two important special triangles
1. the 45-45-90 right-angled triangle whose sides are in the ratio
1 : 1 : √2
2. the 30-60-90 right-angled triangle whose sides are in the ratio of
1 : √3 : 2
The question to find sin 315° probably says to find it "exactly"
I do these in a 3-step process
1. Where is the angle?
315 is in IV and in IV the sine is negative
2. How far from the x-axis ?
315° is 45° from the x-axis
The answer to this question will always be an angle between 0 and 90, it will be called the "angle in standard position, or ASP)
3. Rewrite the question in terms of the ASP
sin 315 = -sin 45
From your special triangles
sin 45 = 1/√2 or √2/2 after rationalizing
so sin 315 = -sin 45 = -√2/2
- algebra 2 - greg, Sunday, May 16, 2010 at 11:52am
In the matrix below, which element is a1,2?
A. 8 C. 6
B. 5 D. 2
Answer this Question
More Related Questions
- algebra2 - I am taking an online class, and cant understand why when I calculate...
- 8th Grade Algebra-Radicals:Answer Check - Change each decimal to a fraction in ...
- Algebra - Can someone check my algebra answers and help me with the problems I ...
- 8th Grade Algebra: Answer Check - Find the length of the 3rd side of each right ...
- math - Here's my question: Determine if each system has one, two, or no ...
- Algebra check? - Sorry the first post formatted weirdly. 1. 3i - 10 --------- 8i...
- Basic Differential Equation - Hi all. I need help understanding something my ...
- Math help please *calculus* - ok im having a bit of a problem rationalizing ...
- 8th Grade Algebra-Radicals:Answer Check - Write each expression in simplest form...
- Algebra - Can you tell me if my answers are correct for these problems? 1. 3i - ...