Verifying Trig Identities

What's your plan? Please do SOMETHING! If nothing else strikes you, it usually helps to convert everything to equivalent sines and cosines. Give it a go.
 
i literally know nothing. i dont even know where to start. im sorry. i just really need some help on these problems :(
 
Use the addition formula for cos:

\(\displaystyle cos(x+y)=cos(x)cos(y)-sin(x)sin(y)\)

Make the cancellations and it works out.
 
bobbyflay21 said:
i literally know nothing. i dont even know where to start. im sorry. i just really need some help on these problems :(
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If this is true, you are in the wrong class. Please have a heart-to-heart talk with your academic advisor.
 
if i make the cancellations it would turn into

cos(y)- sin(x) = cot(y)-tan(x)

how does that manage to verify?
 
bobbyflay21 said:
if i make the cancellations it would turn into

cos(y)- sin(x) = cot(y)-tan(x) <<<< How did you get that - I think you are making mistake in simple division

how does that manage to verify?
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i went from the beginning of the problem and turned the left side into:

cos(x)cos(y) - sin(x)sin(y) / sin(y)cos(x)

then simplified to:

cos(y)-sin(x)
 
bobbyflay21 said:
i went from the beginning of the problem and turned the left side into:

cos(x)cos(y) - sin(x)sin(y) /[ sin(y)cos(x) ]

then simplified to:

Like I said - you are making mistakes during division.

cos(y)/sin(y) - sin(x)/cos(x)
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