Use basic identities to simplify the expression.
\[\frac{ \cos ^{2} \theta }{\sin ^{2}\theta } +\csc \theta \sin \theta \]
answers are A. csc2θ B. sec2θ C. 1 D. tan2θ
keep in mind that \(\bf tan(\theta)=\cfrac{sin(\theta)}{cos(\theta)}\qquad tan^2(\theta)=\cfrac{sin^2(\theta)}{cos^2(\theta)}\\ \quad \\ \quad \\ csc(\theta)=\cfrac{1}{sin(\theta)}\) so replace respectively
notice that \(\bf csc(\theta)sin(\theta)\implies \cfrac{1}{\cancel{sin(\theta)}}\cancel{sin(\theta)}\)
Also can someone \[\cos x-\sin ^{2}x-1\]Factor the algebraic expression below in terms of a single trigonometric function.
the answer to the first one is D correct
use the pythagorean identities
the what?
but how can u explain the second one
notice the 1st identity if you solve for \(\bf sin^2(\theta)\) what would you get?
|dw:1389052240284:dw|
1?
1? whatever happened to the cosine?
oh yeah im so confused
ok... lemme put it this way a + b = 1 solve for "a" what do you get?
b-1
1-b
|dw:1389052562167:dw|
positive?
right, so \(\bf \begin{array}{llll} sin^2(\theta)+&cos^2(\theta)=&1\\ a+&b=&1\\ \end{array}\qquad \begin{array}{llll} \color{red}{sin^2(\theta)}=&1-&cos^2(\theta) \\a=&1-&b\\ \end{array}\\ \quad \\ \quad \\ cos(x)-sin^2(x)-1\implies cos(x)-[\color{red}{1-cos^2}]-1\)
well. sorta missed, the "x", but anyhow, just distribute and simplify
and the answer is csc^2(x)
or (cosx+2) (cosx-1)
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