Question

Complete the identity. sin(a +β)/cos a cos β =


A. cot α + cot

B. tan α + tan

C. tan β + tan α

D. -tan α + cot β

Answer 1

you must be familiar with sin(a+b) identity ?

Answer 2

The trig. identities are important identities that involve sums or differences of angles. An identity that shows that the cosine of the difference of two angles is related to the cosines and sines of the angles themselves. This identity is given below (A and B are used in place of alpha and beta, respectively since HTML does not support Greek characters).

cos (A - B) = (cos A)(cos B) + (sin A)(sin B)

The figure below gives a graphical representation of the cosine identity.



This identity is useful when you are asked to find the cosine of a non-30o-45o-60o-90o angle, such as 10o. Example:

Answer 3

OK @shelbygt520

Answer 4

woah! :O

Answer 5

this should give you all you need to know: http://web.cerritos.edu/dford/SitePages/Math_140/Math140Lecture12_sp07.pdf

Answer 6

its a pdf that I had for my students back when I was a highschool teacher

Answer 7

OK @shelbygt520

Answer 8

old but it works

Answer 9

is it either A or C

Answer 10

I don't know what do you think

Answer 11

lol, tell you what, @Girl_Ninja , I'll let you have one guess... if it's right, great, you're lucky, if it's wrong, I'll tell you it's wrong, but I'll no longer confirm further guesses... at least it would get your choices down to three :)

Answer 12

I think @terenzreignz is correct well give you 2 chances ill answer one and he can answer the other

Answer 13

ok @terenzreignz C

Answer 14

@shelbygt520 A

Answer 15

One of these is correct.

Answer 16

Someone's been cavorting with Lady Luck... as promised, since it was addressed to me, you're right with letter C @Girl_Ninja Nice guess :P

Answer 17

But, let's put up why...

Answer 18

shut up a is pellet and c is $

Answer 19

THANKS @terenzreignz OK

Answer 20

yep @terenzreignz great job you did it

Answer 21

The identity...
sin(A + B) = sin(A)cos(B) + cos(A)sin(B)

Then we have
\[\Large \frac{\sin(\alpha + \beta)}{\cos(\alpha)\cos(\beta)} =\frac{\sin(\alpha)\cos(\beta) +\cos(\alpha)\sin(\beta)}{\cos(\alpha)\cos(\beta)}\]

Answer 22

WELL WHATS THE DIFFERENCE BETWEEN B AND C

Answer 23

I don't know, your B is typed incompletely...

Answer 24

lets go over to @stepennd7

Answer 25

O ITS
A. cot α + cot β

B. tan α + tan β

C. tan β + tan α

D. -tan α + cot β

NOW IN THINKING IT B

Answer 26

@terenzreignz

Answer 27

then there is no real difference between B and C... @shelbygt520 ?

Answer 28

although, if you had to choose, go for B.

Answer 29

OK THANK TOU SO MUCH FOR YOUR TIME @terenzreignz AND @shelbygt520

Answer 30

not a problem that's what we are here for

Answer 31

Well, guys, I'm feeling sleepy... I think I'll sign off for now :) Have fun :D
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Terence out

Answer 32

LOL OK @terenzreignz

Answer 33

same here 67 lock

Answer 34

;-) @shelbygt520