Evaluate following unit circle, Mathematics

Assignment Help:

Evaluate following sin 2 ?/3   and sin (-2 ?/3)

Solution: The first evaluation in this part uses the angle 2 ?/3.  It is not on our unit circle above, though notice that  2 ?/3= ? - ?/3 .  thus 2 ?/3 is found through rotating up from the -ve  x-axis.

It means that the line for 2 ?/3 will be a mirror image of the line for ?/3 only within the second quadrant. The coordinates for 2 ?/3   will be the coordinates for ?/3 except the x coordinate will be negative.

Similarly for - 2 ?/3 we can notice that - 2 ?/3  = - ?+  ?/3   , hence this angle can be found by rotating down ?/3   from the -ve x-axis. It means that the line for ?/3  will be a mirror image of- 2 ?/3 the line for ?/3  only in the third quadrant and the coordinates will be the same as the coordinates for ?/3  except both will be negative.

Both of these angles along with their coordinates are illustrated on the following unit circle.

2251_unit circle point.png

From this unit circle we can see that sin ( 2 ?/3  ) =√3/2 and sin ( -2 ?/3  )=√3/2

It leads to a nice fact regarding the sine function. The sine function is known an odd function and hence for any angle we have

                                          sin ( - θ ) = - sin (θ )


Related Discussions:- Evaluate following unit circle

How much will it have depreciated after 2 years, The value of a computer is...

The value of a computer is depreciated over ?ve years for tax reasons (meaning that at the end of ?ve years, the computer is worth $0). If a business paid $2,100 for a computer, ho

Find the third vertex of equilateral triangle, If two vertices of an equila...

If two vertices of an equilateral triangle are (0, 0) and (3, 0), find the third vertex. [Ans: 3/2 , 3/√ 3/2  or 3/2, -3√ 3/2] Ans:    OA = OB = AB OA 2 = OB 2 = AB 2

Discrete, For each of these arguments determine whether the argument is cor...

For each of these arguments determine whether the argument is correct or incorrect and explain why. a) Everyone enrolled in the university has lived in a dormitory. Mia has never l

Explain the rules of divisibility, Explain the rules of Divisibility ? ...

Explain the rules of Divisibility ? Divisible by 2: If the last digit is a 0, 2, 4, 6, or 8, the number is evenly divisible by 2. Divisible by 2 Not

construct an isosceles triangle, 1. Construct an isosceles triangle whose ...

1. Construct an isosceles triangle whose base is 7cm and altitude 4cm and then construct another similar triangle whose sides are 1/2 times the corresponding sides of the isosceles

Area, find area of rectangles and triangles put together

find area of rectangles and triangles put together

Laplace transforms, As we saw in the previous section computing Laplace tra...

As we saw in the previous section computing Laplace transforms directly can be quite complex. Generally we just utilize a table of transforms when actually calculating Laplace tran

Find the determinant and inverse matrix, Find the Determinant and Inverse M...

Find the Determinant and Inverse Matrix (a) Find the determinant for A by calculating the elementary products. (b) Find the determinant for A by reducing the matrix to u

Arc Length and Sector Area, how do i find the diameter of a circle if i hav...

how do i find the diameter of a circle if i have the shaded sectors area of 263.76 and the central angle of that circle is 210 degrees?

Direction fields, This topic is specified its own section for a couple of p...

This topic is specified its own section for a couple of purposes. Firstly, understanding direction fields and what they tell us regarding a differential equation as well as its sol

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd