Simplify the trigonometric expression.
@kola908
do you have your list of trig identities?
No idea how to do this! sorry
let me see you try to solve without thinking that sine is sine. think of it as regular x and see where that will take you
\[\frac{ 1 }{ 1+x }+\frac{ 1 }{ 1-x }\] can you solve this?
I told you I have no idea how to do this.. sorry..
hmm can you solve this ?\[(1-x) (1+x) \]
1x^2
?
"FOIL" method
\[(A+B) (A-B) = A*A -A*B +A*B+B*B \] simplifies to \[A^2+B^2\]
ok
\[1+\sin^2\theta \] right?
are you making any connection?
means 1
I think you need help way beyond trigonometry :(
going back to introduction to algebra
@nincompoop I'm sure you meant \(\large (A + B)(A - B) = A^2 \color{red}- B^2\) and \( \large (1 + \sin \theta)(1 - \sin \theta) = 1 \color{red}- \sin^2 \theta\)
uyeah thanks for correcting
yw
can someone just please show me step by step please
You are adding two fractions. That means you need a common denominator.
The LCD is \( (1 + \sin \theta)(1 - \sin \theta) \)
\[1-\sin^2 \theta = \cos^2 \theta\]
We need to multiply the left fraction by \( \dfrac{1 - \sin \theta}{1 - \sin \theta}\) and the right fraction by \( \dfrac{1 + \sin \theta}{1 + \sin \theta}\)
see \[\frac{ 1 }{ \cos \theta } = \sec \theta\] you don't have to know a lot you just need to make sure you can start deducing the possible answers
so this means that our answer contains \[\sec^2 \theta\]
A... 2 Sec^3 O
it can't have an order magnitude of 3 because our denominator has only an order of 2
well its the only answer with sec
Please this is my last question...
i meant 2 sec 2... look at A
\(\dfrac{1}{1 + \sin \theta} + \dfrac{1}{1 - \sin \theta} \) \(= \dfrac{1}{1 + \sin \theta} \times \dfrac{1 - \sin \theta}{1 - \sin \theta} + \dfrac{1}{1 - \sin \theta} \times \dfrac{1 + \sin \theta}{1 + \sin \theta}\) \(= \dfrac {1 - \sin \theta} {(1 + \sin \theta)(1 - \sin \theta) } + \dfrac{1 + \sin \theta}{(1 + \sin \theta)(1 - \sin \theta)}\)
Im choosing A
you are correct but you need to know the techniques
\(= \dfrac {1 - \sin \theta} {1 - \sin^2 \theta } + \dfrac{1 1 + + \sin \theta}{1 - \sin^2 \theta}\) \(= \dfrac {1 - \sin \theta +1 - \sin^2 \theta }{1 - \sin^2 \theta}\) \(= \dfrac {2}{\cos^2 \theta}\) \(= 2 \sec^2 \theta\)
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