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Recent content by kasser

  1. K

    Proof by contradiction

    prove the cube root 2 is irrational?
  2. K

    How to solve?

    AB is a diameter of a circle and CD is a chord drawn perpendicular to A cutting it at X. Prove that CX ^2 = AX.XB
  3. K

    Probability help

    In a random experiment Pr(A) = 0.6 Pr(B)=0.54 and Pr (A intersection B') = 0.4 What is the intersection? Apparently it is 0.2? how do we achieve this?
  4. K

    Diagram? working out?

    A road run due east from A to B a distance of 1500m. A church bears 140 degrees from A and 170 degrees from B. How far is the church from B?
  5. K

    Which liquids are polar and non polar? Why?

    Tap water Distilled Water Ethanol Kerosene Hexane ?
  6. K

    Just question e iii) ?

    attached below Just e iii) the magnitude of an angle. Is the working out for the angle like this sin inverse -3/5 + sin inverse 12/13 = 104.25 degrees However, this method does not work for cosine (a-b). It only worked for sine(a-b) and tangent (a-b)
  7. K

    how to solve?

    sin identities in attachment
  8. K

    2cos(pi/4 + theta)cos(pi/4-theta)?

    How would you simplify 2cos(pi/4 + theta)cos(pi/4-theta)? The overall answer should be cos squared theta - sin squared theta = cos2theta
  9. K

    Is 1-sin^2 (pi/2-theta) simplified to 1 sin^2 theta?

    simplify 1-sin^2 (pi/2-theta) I think the answer is 1-sin^2 theta But apparently the overall answer is just sin^2 theta??:eek2:
  10. K

    HELP!! How to solve these circle geom questions !

    Thankyou, this actually helped, i think i learned something new :)
  11. K

    Why type of bond is BF3?

    I believe BF3 is a covalent bond but when i calculate the electronegativity difference between them i get a value of 2. The electronegativity of B=2.0 and F=4.0 therefore F-B = 2 Apparently if the Electronegativity difference lies between these values it determines what type of bond...
  12. K

    Type of bond? BF3

    BF3 should be a convent bond, since two non metal elements? However, when you calculate the Electronegativity difference of the molecule I get a value of 1.9. 0-1.7 = convalent bond and 1.7-3.3 = ionic bond 1.9 lies in the ionic bond category?
  13. K

    Molecular shapes-Feedback?

    Which of the following statements best describes the structure of solid carbon dioxide: a. it is an array of positive carbon ions and negative oxide ions b. each carbon atom is joined by strong covalent bonds to four oxygen atoms to give an array of many thousands of atoms c. molecules...
  14. K

    HELP!! How to solve these circle geom questions !

    1)Two circles touch internally at A. The tangent at P on the smaller circle cuts the larger circle at Q and R, prove AP bisects angle RAQ? 2)PA and PB are two tangents to a circle and x is the midpoint of minor arc AB.Prove XA bisects angle PAB and XB bisects angle PBA? 3)AB and CD are...
  15. K

    Geometry 2

    How to solve? If two chords, AB and CD, of a circle bisect each other, prove that the chords are diameters of the circle Thanks:haha:
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