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# Trigonometry--identity proof question,help

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1. need help plz for Q)10 part b and c
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2. (Original post by lil_jack)
need help plz for Q)10 part b and c
What have you tried? For (b) multiply the LHS by so you get the denominator as you want and you get a difference of two squares in the numerator that you can Pythagoras and cancel with the denominator.

For (c) turn everything into sines and cosines and then make common denominators and then use a nice identity in the numerator.
3. cross multiply in b because one is plus one is minus so they cancel out and your answer is one. c is too hard i havent learnt tan yet
4. (Original post by white.daniel)
cross multiply in b because one is plus one is minus so they cancel out and your answer is one. c is too hard i havent learnt tan yet
No, that's incorrect.
5. (Original post by Zacken)
No, that's incorrect.
did they mean to write a plus on the left side becuase plus doesnt equal minus sign
6. (Original post by white.daniel)
did they mean to write a plus on the left side becuase plus doesnt equal minus sign
sigh, no, your logic is just wrong. You're doing when you should be doing
7. (Original post by white.daniel)
theres no a in the question, were looking at part b here

are you pulling my leg here?
No - guess you're another troll. Ignored and reported.

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