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Find sin 2x, cos 2x, and tan 2x if cosx= 5/13 and x terminates in quadrant IV.

User Itthrill
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1 Answer

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Step-by-step explanation:

Consider the following expression:


\cos(x)=(5)/(13)

this expression can be represented in the following right triangle:

To find y, we can apply the Pythagoras theorem as this:


y=\sqrt{13^2\text{ - 5}^2}\text{ = 12}

but since x terminates in quadrant IV, we have that


y=\text{ - 12}

and thus


\sin(x)=\text{ -}(12)/(13)

and


\tan(x)=\text{ -}(12)/(5)

now, using this data in the following formulas:

we can conclude that the correct answer is:

Answer:


\sin(2x)=\text{ -}(120)/(169)
\cos(2x)=\text{ - }(119)/(169)
tan(x)=(120)/(119)

Find sin 2x, cos 2x, and tan 2x if cosx= 5/13 and x terminates in quadrant IV.-example-1
Find sin 2x, cos 2x, and tan 2x if cosx= 5/13 and x terminates in quadrant IV.-example-2
User Feofilakt
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5.2k points