Question

Reciprocal of 2cos(2x)?
Help for a medal?

Answer 1

Skip the medal part; it's unnecessary.

What does reciprocal mean to you? What is the reciprocal of 3?

Answer 2

The reciprocal of 3 is 1/3 I believe

Answer 3

right. What is the reciprocal of cos x?

Answer 4

1/secx

Answer 5

why do you believe division is necessary here?

Answer 6

"reciprocal of cos x" looks like 1 / cos x

Answer 7

I just have the reciprocal identities memorized

Answer 8

at least I thought I did

Answer 9

The reciprocal of cos x is .... what? no fraction necessary.

Answer 10

Either memorize the fact that the rec. of cos x is sec x, or actually write 1 / cos x and recall that the equivalent of 1 / cos x is sec x.

Answer 11

The reciprocal of sin x is 1 / sin x, or csc x.

Answer 12

The reciprocal of tan x is 1 / tan x, or cot x.

Answer 13

The recip of cos x is .... ?

Answer 14

1/cosx

Answer 15

Yes, and that is also equal to ... ????

Answer 16

secx

Answer 17

Very good!

Answer 18

I've used this reference in the past (referring to the 2nd page). http://tutorial.math.lamar.edu/pdf/Trig_Cheat_Sheet.pdf Is it not correct?

Answer 19

Reciprocal of 2cos(2x)?

Answer 20

2sec2x?

Answer 21

or 2(1/cos(2x))

Answer 22

Your table of formulas is great, just fine, correct.

Answer 23

Wait...so cosx reciprocal can also been represented as 1/secx?

Answer 24

Reciprocal of 2cos(2x)? You have to put all of 2cos(2x) in the denominator.

1 / ( ? )

Answer 25

cosx = 1 / sec x, YES

sec x = 1 / cos x YES

Answer 26

Reciprocal of 2cos(2x)?

Answer 27

1 / ( sec(2x) )

Answer 28

no

Answer 29

I take that back

Answer 30

OK

Answer 31

try again

Answer 32

2 / ( sec(2x) )

Answer 33

Reciprocal of 2cos(2x)? All of " 2cos(2x)" goes into the DENOMINATOR.

Answer 34

Oh so it's 1 / (2cos(2x)).

Answer 35

Right. Or, (1/2)(1 / cos 2x )

Answer 36

What is the trig identity for 1 / cos 2x?

Answer 37

cos2x

Answer 38

Sorry, I didn't think. Try answering my question again.

Answer 39

Review our past conversation.

Answer 40

cos 2x is not the reciprocal of cos 2x.

Answer 41

Reciprocal of 2cos(2x)?

Answer 42

"cos 2x is not the reciprocal of cos 2x"
That I understand.

"Try answering my question again."
Which question?

Answer 43

Reciprocal of 2cos(2x)?

Answer 44

1 / (2cos(2x))
or
1 / (2sec(2x))
or
2sec(2x)

Answer 45

correct?

Answer 46

Actually, (1/2)sec (2x). This follows the pattern we established earlier.

Answer 47

recall that the recip. of 2 is (1/2).

Answer 48

Apologies. My page keeps reloading itself, and I'm not sure why.

Answer 49

Same here.

Answer 50

Reciprocal of 2cos(2x)? Find the recip. of 2 and then the recip of cos 2x, and mult. the 2 recips together.

Answer 51

So it can also be (1/2)(1/cos(2x)) = 1/(2cos(2x))

Answer 52

Your first form is correct, and so is the second. However, it's better to write (1/2)sec 2x.

Answer 53

So for the reciprocals of cosx...
1/cos(x) and sec(x) both work, but 1/sec(x) is the best way to show it?

Answer 54

1/sec(x) is the best way to show it? No. recall that 1/cos x = sec x.

Answer 55

You were finding the recip of 2 cos 2x, which is (1/2)*(1/cos 2x) = (1/2)(sec 2x) END

Answer 56

Yes. I was just using the cos(x) as an example.

Answer 57

Thx for your patience. Clear on this? Further questions?

Answer 58

I think I got it. Thank you!

Answer 59

You're very welcome. Take care!

Answer 60

Thx for the3 medal!

Answer 61

I know you said no medal, but I'm thankful.
You're welcome. :3

Answer 62

See y ou again! Bye.

Answer 63

Good bye. :)