Recent content by cormglakes

  1. C

    complex number question

    oh that makes way more sense now... lol i was trying to do cis and all that stuff
  2. C

    mechanics problem

    How do you do part b? An object falls from the top of a building. An office worker sees the object fall past a window 2 m high in 1 5 s. Assume that air resistance is negligible and use g = 10 m/s^2 . Let y be the height of the object above the bottom of the window at time t. (a) Show that y = H...
  3. C

    mechanics question

    Hey how do I do part c? a) Prove that the range on a horizontal plane of a particle projected upwards at an angle A to the plane with velocity V meters per second is (V²sin 2A)/g meters A garden sprinkler sprays water symmetrically about its vertical axis at a constant speed of V meters per...
  4. C

    motion question

    A boat has a speed relative to the water at 3m/s. The boat points 35 degrees to the shore, moving upstream on a river flowing 0.75m/s. How much time does it take for the boat to reach the opposite shore if it the river is 50m wide?
  5. C

    binomial question

    I know how to do question a but how do I do question b? I think Im pretty close - my integration result looks pretty similar to what ive proved but i dont know what to sub in; subbing in -1 or 1 should work but it doesnt work for me
  6. C

    binomials

    how do i solve nC4 + nC5 =12C5 answers : n=11
  7. C

    complex number question help!!!

    sorry yea the answer is -4,0
  8. C

    complex number question help!!!

    how do i do question ii: and this question ANS k = -4, 0
  9. C

    proofs question

    Also another proofs question, how the bloody hell do u prove : a/(b+c) + b/(a+c) + c/(a+b) > 3/2 also does anyone have proofs tips? coz i rlly suck at proofs.
  10. C

    proofs question

    so i can do question A by doing LHS- RHS and then doing 2 cases where a>b and a<b so show LHS - RHS >0 ; is there and alternative solution? and for B and C, I have absolutely no clue.; for B i think you have to add multiple inequalities but i am not sure what inequalities.
  11. C

    complex numbers trig identities

    mastering maths textbook
  12. C

    complex numbers trig identities

    i know how to get a,b,c but how do you get d? for d, i got another answer using the same method i used for c but cant get the correct result.
  13. C

    complex number question

    and then after I get cosx=0 --> z= i & -i and cosx=2 --> how do I find the other 2 roots?
  14. C

    complex number question

    let z=cosx + isinx solve z^4 - 4z^3 + 2z^2 - 4z+1 = 0
  15. C

    trig

    sorry let me fix that
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