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    Inverse trig problem

    Find the volume of the solid formed if the curve y = sec^-1(x) is rotated about the x-axis from x = 0, 0.5, using the trapezoidal rule with 5 subintervals. MIF challenge exercise 7 Q10 (a Thanks for any help. I get a different answer to BOB.
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    Baseball probability combs question

    A squad of 8 is chosen at random from 3 baseball teams with 10 players in each team. Find the probability that Joe from the B team and Dan from the A team will be chosen. My answer: (28C6 . 2C2)/ 30C8 = 28/435...
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    Trig question from mathsonline

    A triangle ABC is right-angled at C. Angle BAC = theta. D is the point on AB such that DC is perpendicular to AB. i) You are given that 2AD + 7BC = 5AB Simplify: 2cos theta + 7tan theta ii) Hence find theta
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    Expand tan(x+2y)

    Expand tan(x+2y) I get this far (tanx+2tanx/(1-〖tan〗^2 x))/(1-tanx 2tany/(1-〖tan〗^2 y)) but then I can't get to the answer in BOB. Please help!
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    Tank question

    Can anyone help me with this. The flow rate of water out of a hole in a tank is known to be proportional to the squareroot of the height of water above the hole. That is, dV/dt = sq root(h) Suppose the tank has constant cross-sectional area A, show that the height of the water in the...
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    Flow rate

    Can someone help me with this. The flow rate of water out of a hole in a tank is known to be proportional to the squareroot of the height of water above the hole. That is, dV/dt = sq root(h) Suppose the tank has constant cross-sectional area A, show that the height of water in the tank is...
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    1 = 0

    l og3 81 = x then 3x = 81 3x = 34 therefore x = 4 11= 1 10 = 1 11 = 10 1 = 0 Why is this wrong / right ????
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    Growth and decay question

    The velocity of a particle is given by v=100 + 280e^-kt ms^-1 . If the velocity decreases by 20% after 50 seconds , find the % decrease in velocity after 3 minutes.
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    Inflexion point for y = x loge x-x^2

    Having problems with this one. Find the point of inflexion on the curve y = x loge x-x2 Can anyone help?
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    Series question from challenge exercise 8

    Find the sum of the first 20 terms of the series 5 - 2 + 10 - 8 + 15 - 32 + 20 - 128 + ....
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