Ask your own question, for FREE!
Mathematics 20 Online
OpenStudy (dtan5457):

Trig identity simplification check

OpenStudy (dtan5457):

\[\frac{ \sin(-x) }{ cscx}+\frac{ \cos(-x) }{ secx }\]

OpenStudy (dtan5457):

Each one is -1, so I believe this adds up to -2.

OpenStudy (dtan5457):

@SithsAndGiggles

OpenStudy (anonymous):

That's not true. \(\dfrac{\sin x}{\csc x}=\dfrac{\sin x}{\frac{1}{\sin x}}=\sin^2x\neq1\).

OpenStudy (anonymous):

\(\cdots\neq-1\) for that matter.

OpenStudy (dtan5457):

Oh, divided this incorrectly.

OpenStudy (dtan5457):

well in that case, would this be.. sin^2x+cos^2x=1?

OpenStudy (anonymous):

Not quite. \[\sin(-x)=-\sin x\] which means \[\frac{\sin(-x)}{\csc x}=-\sin^2x\] while \[\cos(-x)=\cos x\] so \[\frac{\cos x}{\sec x}=\cos^2x\] but \(-\sin^2x+\cos^2x\neq1\).

OpenStudy (dtan5457):

uhh..

OpenStudy (dtan5457):

what rule should i use?

OpenStudy (anonymous):

The last line is another identity. Do you remember your double angle identities?

OpenStudy (dtan5457):

dont even think we got up to that lol

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!