Math 10 3.2 Notes Sine and Cosine Ratios Cosine and Sine ratios: - We have learned about tangent ratios. - Sine and Cosine ratios follow the same process except they involve the hypotenuse! .IDA" ~Q--8J t l' l' S\ 1\<-- off h~ p Sin A = ----=:;-+-L.-_ -CA--~ Cos A = ~.()..._d.~~....-_ hjP Ex 1) Find sin Band cos B: S,(1 ~ -.::: ofe \~f _ ~J.. -~- ;)lc; 1
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3.2 Notes Sine and Cosine Ratios Cosine and Sine ratios · 2019. 11. 29. · 3.2 Notes Sine and Cosine Ratios Cosine and Sine ratios: - We have learned about tangent ratios. - Sine
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Math 10
3.2 Notes
Sine and Cosine Ratios
Cosine and Sine ratios:
- We have learned about tangent ratios.
- Sine and Cosine ratios follow the same process except they involve the
hypotenuse!
.IDA"
~Q--8Jt l' l'
S\ 1\<-- off h~ pSin A = ----=:;-+-L.-_
-CA--~Cos A = ~.()..._d.~~....-_
hjP
Ex 1) Find sin Band cos B:S,(1 ~ -.:::ofe
\~f
_ ~J..-~-;)lc;
1
You try ....
_ 1,5 -_O~'3~2.,nooo ~_'.,". Q_ 0 i\ -:L \- '-_ Sin D =.~ \ ~ -::: \ ...,. 'Ies ~jf t). S
F cos E= ,ClJj -:: ~. D_ ~O,)FHsinE =\"\JP CO • ~
Finding an angle:
Just like before, we can use the inverse trigonometric ratio to find the angle!
Al J:j ef ght rasts a 15.'- ladder aga j st a build ing. as sho.•,m. SC)\ \le. rVC>b \ -{N\ .'tV at an gle d 25 the ad;.,;2,," a eo with .c grc r d ?G\(2 Y:JU answ-er:o t e .carestd.cgre2.
'~~L ~ tH\\- L \-\\V( hG\ \l e. ().&~ ) njr .U~~ GOS\f\G (Crr\-\)
.--======-
CJJ~ L \~ - (A o'i =- ,y. r_
hjr \'Stb
c.OS L \-\ ~ 0, S41-\~-lL .\-\= co s-\ (0 ' s 4 '-\-«)\ ')
\LM =~i-:\Using cosine and sine ratios to find unknown lengths
Ex 2: Find the length of RSto the nearest tenth of a metre.()..(,\j
R ~_ S.'opo ./."..r .>..g.~ l
~./ \-\jP'
So \-\ C~ \-\-
Ex 3: A skier races 3514 m down a ski hill. The ski course meets the ground at anangle of 16°. What is the vertical height of the course?
Draw yourself a triangle given any known dimensions and angles.- Label all sides (opp, ad], hypotenuse) cg\S- Then decide which trig ratio will let you answer the question
o Remember SOH CAH TOA !
If you are looking for a length, use the ratio e. -c : .:s \ {\ e =- \,~~If you are looking for an angle, use the inverse ratio u