View Full Version : Does this answer make sense?
supernova1203
Mar19-11, 10:35 AM
Trig ratios identities problems, in this case i am not asked to prove anything, just asked to simplify(Solve)
im left with
(1/costheta)(1/costheta)
At this point do we cross multiply?
we would end up with
costheta/costheta = 1
does this make sense? I encountered a similar problem earlier and it was somewhat like this where the solution was 1.
niklaus
Mar19-11, 10:49 AM
are you saying that from
x = (1/cos(theta))(1/cos(theta))
you arrive at cos(theta)/cos(theta) = x = 1?
that would not be correct...
however the statement
cos(theta)/cos(theta) = 1 would certainly be correct
mharten1
Mar19-11, 10:57 AM
No, it isn't correct.
You do not cross multiply unless they are equal to each other. In this case, you should multiply normally. You started with (1/cosθ)(1/cosθ), correct?
So in that case (1/cosθ)(1/cosθ) = 1/cos2θ = sec2θ
Yes it doesn't add up
For example 1/cos(theta) x 1/cos (theta) is the same as saying 1/cos^2(theta) does this equal 1?
Find a trig identity that would explain it in different terms I think is your best bet.
Ok that was redundant whs^. :smile:
HallsofIvy
Mar21-11, 05:24 AM
\frac{1}{a}\frac{1}{a}= \frac{1}{a^2}
not 1.
If you were dividing, it would be
\frac{\frac{1}{a}}{\frac{1}{a}}= 1
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