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Find the exact value of each trigonometric function using the unit circle ​

Find the exact value of each trigonometric function using the unit circle ​-example-1
User Mehrdad Safa
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1 Answer

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15 votes

Answer:

Explanation:

8)

co-terminal angle for -960... can you tell me? :D w/o looking at my answer below?

Your answer for co-terminal angle is ______________ :)

960 - 360 = 600

600 - 360 = 240

this is telling us that going in a clock wise direction.. as the -960 is, that the co-terminal angle is 240, which seems about right.. looking at the graph. so now. let's take 240 away from 360 to find that co-terminal angle but going in the positive direction or the counter clock wise direction

360-240 = 120

and yes.. that does look like 120 ° going in the positive direction.

now do you know the sec identity to use sin and cos???

look at the below diagram

sin sec

cos csc

tan cot

the trig function line up like that for a reason

sin 1/sin

cos 1/cos

sin/cos cos/sin

I put them in their sin and cos identities.. see.. they all line up that way

sec = 1/sin

csc = 1/cos

tan = sin/cos

cot = cos/sin

now... find

sec(120) = 1/sin(120)

do you know how to find sin(120) ?????

put it back to it's co-terminal angle in the 1st quadrat... I hope you know how to do this.. i'll just speed along... assuming you do

sin(120) = sin(60)= √3/2

so sec(120) = 1 / √3/2

so sec(120) = 2/ √3

10)

csc(315) = 1/cos(315)

find the co-terminal angle that you know in the 1st quadrant again...

so 315 = 45 in the 1st quadrant.. I just looked and can see that

so

csc(315) = 1/cos(315 = 1/cos(45) and cos(45) = √2/2

so then 1 / √2/2 = 2 / √2

csc(315) = 2 / √2

what i'm really wondering about.. is .. where is question 9)

:DDD

User Cristian Babarusi
by
3.4k points