Introduce yourself?

hi friends!  i have started this blog spot for we were assigned an assignment in math on trigonometry.There is one person on here and you may have already seen on and think why recognise 'judy & paul'? we are in one group so i'd like to also include them here aswell (:

you have may stumbled upon this whether it may be you're already a friend or, just happen to really enjoy maths, as much as we do, especially with a down to earth teacher like ours.
p.s (just a LITTLE sucking up to get a higher grade)

no, but sincerely he is what makes maths a joy. 

hope after every lesson you learn something new and hoping that at the end of each blog post you'll be a step knowledgeable in trigonometry as we are!


p.s now scroll down all the way to the second post as that is where the lessons begin (:

xx

judy, hannah & paul

Problems involving Bearings

//trigonometry lesson #8 
p.s last lesson :( 

it has honestly been such a joy to teach ya'll out there whoever you may be or where ever you may be but we really enjoy this blog post and hopefully these post definitely made a difference. thanks for the views and honestly did not expect this much!! thank you friends sooooo much!!!! xxx


here it is! the last lesson// b e a r i n g s

Examples:

this calculator is recommended for this lesson (fx82au PLUS)

problem:  A cyclist travels 10 km south, then 8 km east. Find the cyclist's bearing from her starting point to the nearest degree.

Solution:

so if we want to find θ we have to focus on △OAB, become θ  8km = opp 10km = adj
opp    (TOA)
adj 
                                                                  
tan θ = 8/10 
press into calculator shift tan (tan -1)

= 0.8

nearest degree

= *enter into calculator [bubbles]   
= 39 (degrees)         

the bearing from B to O 
= 180 (degrees) - θ 
= 180 (degrees) - 39 (degrees)
= 141 (degrees) 

therefore the cyclist bearings from B to O is 141 (degrees) from her starting point. 

judy, hannah & paul

Angles of Elevation and Depression

//trigonometry lesson #7

hey all! so as we are nearing the end we just wanna thank you for all the views and hope that at the end you're now as great as we are in trigonometry!

but for now lets look at angle of elevation depression friends!! xx

Example 1:

Angle of elevation is the angle of looking up, measured from the horizontal. 

Angle of elevation

Angle of depression is the angle of looking down, measured from the horizontal. 

Angle of depression 

judy, hannah & paul

Finding an angle

//trigonometry lesson #6 

hey ya'll, we're leading up to our last few lessons and we all hope that ya'll are learning soemthing new after every blog post!

but for now let's learn more on finding the angle!


today's lesson we'll be looking more towards finding an angle. 


Example:

(c) = 13m

(a) = 9m 

if we look at this right- angled triangle since already know that a right angle is 90 degrees we're going to find theta (θ) using a calculator.

sin θ = opp  

           hyp

sin-1 = (9/13)

   

θ = 43.8

          

Solution:

SOH, CAH or TOA??

Use sin because O and H are known.

sin θ = 9

         13

θ = 43.813 ...

θ = 43.8

judy, hannah & paul

Finding the length of a side

// trigonometry lesson #5

this is the calculator recommended for this lesson (fx82au PLUS) 

hey world! today we'll be learning to find the length of a side of a right-angled triangle. So lets get started!!



Step 1: Remember to label the triangle! H (hypotenuse), O (opposite) and A (adjacent).
Step 2: Choose whether sin, cosine or tangent should be used.
Step 3: Write an equation or formula using the correct ratio.
Step 4: Make the pro numeral the subject.
Step 5: Use a calculator to find or evaluate the answer.

Here is an example:

Example:
Find the value of the pro numeral in this right-angled triangle, correct to two decimal places.

Solution:
SOH, CAH or TOA?
Use cos because A (adjacent side) and H (hypotenuse) are marked.

          cos 50 (degrees) =  adjacent 
                                    hypotenuse
          cos 50 (degrees) =          y       
                                      hypotenuse
cos 50 x 8 =    y   x 8          (mulitply both sides by 8)
                     8
8 cos 50 = y
          y = 8 cos 50
             = 5.142300877...
          y = 5.14                  (round of to 2 d.p)

judy, hannah & paul

Using the calculator to find angles

// trigonometry lesson #4

helloooo, this lesson you will be learning about finding angles and using a calculator to help you find the angle (:



let's get into it..

this is the calculator we recommend for this lesson ( fx82au PLUS)

to find an angle of a triangle, use inverse sine, cosine and tangent. press shift sin, cos and tan.

Finding an angle:
Example:
sin θ = 0.85
sin (sin θ) = sin-1 (0.85) 

Solution:
Enter Shift sin 0.85 into the calculator
= 58.21
= press [bubbles] = 58.2 (degrees) 

judy, hannah & paul 

Trigonometry Calculator Form

// trigonometry lesson #3

this blog will teach you how to do SOH CAH TOA in your calculator. through this, you will find the degree, minute and seconds of a triangle. 

this is the calculator we use during math class (recommended: fx82au PLUS)

In trigonometry, angles are usually measured in degrees, minutes and seconds. The key relationships are:

1 degree = 60 minutes

1 = 60'

and

1 minute = 60 seconds

1' = 60''

This is what the degrees, minutes and seconds key on the calculator looks like.
we like to call it: [bubbles]

To find the nearest degree:

Example:

46 (degrees) 45' = 46.75 (decimal)

Solution

Enter 46 (degrees) 45' into calculator

46 [bubbles] 45' [bubbles] = Press [bubbles] = 46.75 (degrees)

To find the nearest minute:

Example:

75 (degrees) 30' 18'' = 75 (degrees) 30'

Solution

if the seconds is 30 or above, the nearest minute would be add one minute.

18 is not 30 or higher, therefore the 30 minute would remain. 

hoping that you now got the technique of finiding the nearest degree and minute on calculator. see you in our next post!!

judy, hannah & paul