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Is this true or false?


sin(x−5)=cos(4x+10) when x=17

 Mar 17, 2019

First off we want to note that sin(x) = cos(90-x)


Then if you plug in 17 for x you get:


sin(17-5) = cos(4*17+10)

which is

sin(12) = cos(78)


now lets see if this equation is equal by using sin(x) = cos(90-x)

so x would be 12 in this case.



sin(12) = cos(90-12)


sin(12) = cos(78)


this is the same answer that we got before (in bold)

so the statement is true

 Mar 17, 2019

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