Odd - even properties to find the exact value

alyren

Junior Member
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Sep 9, 2010
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if f(data) = tan data and f(a) =6, find the exact value of f(-a)

is f(-a) =-6?
 


The tangent function is an odd function.

Make use of the even-odd identity for tan(data).

I mean, for example, sin(data) is odd, too.

sin(-a) = -sin(a), yes?

cos(-data) = cos(data) because the cosine function is not an odd function; it's even.

So, what do you think tan(-a) equals?

That's f(-a), the opposite of f(a), which is given.

8-)

 
So its not f(-a)= -6?
(i knew tangent is odd)

i thought i have to find f(-a) not tan(a). the given tan data is just to tell you that tan data is odd.

so if given equation is f(a)=6
the opposite would be f(-a)=-6???
 
alyren said:
So its not f(-a)= -6?

No, it is -6.

Please excuse me; I think that I must have skipped over the second line of your original post.

I mean, I did not realize that you had already asked this question.

f(-a) = -6 because f is an odd function.


i thought i have to find f(-a) not tan(a).

That is correct, but you need to realize that f(-a) = tan(-a)


the given tan data is just to tell you that tan data is odd.

No, I don't think so.

tan(data) is given to DEFINE function f.


In other words, function f and the tangent function are one in the same. They just changed the function's name from "tan" to "f", and data = a.

 
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