Search results

  1. U

    Complex Number Equation

    Good, that is the way I did it too. Thanks. It doesn't say, but the solution was x = 3 in the book as well.
  2. U

    Complex Number Equation

    Shouldn't it read 15 + 3i and x = 3 as the only solution?
  3. U

    Complex Numbers for + Rep

    That's alright, I'll be using it all through Uni. anyway. Converting between Cartesian / Polar / Exponential will be useful. Rep. seems to have disappeared since my last visit...
  4. U

    Complex Number Equation

    Solve (x2+6) + xi = 3(2+3i)(1-i) I ended up with (x2+6) + xi = 15 + 3i & solved xi = 3i to get x = 3. I'm wondering how else people do this?
  5. U

    Complex Numbers for + Rep

    Thank you!
  6. U

    Complex Numbers for + Rep

    Find z1z2 and z12 if z1 = cis(π / 6) & z2 = 3cis(-5π/6) Answer: z1z2 = 3e-2iπ / 3 = 3/2 (-1 - √3i) z12 = eiπ / 3 = ½(1 + √3i) Can someone please show working to reach this? π = pi.
  7. U

    Two easy Q.s for +Rep

    Prove logb(x) = y is equivalent to b^y = x. If logb(x) = 5, then logb(x^2) is equal to? TBH, I'm more interested to see how people prove the log law (second Q. is just bringing down exponent).
  8. U

    Integrate Indefinite Integrals Please

    1. 4x / (2x²+3) 2. x - 1 / x²
  9. U

    Find the equation of the curve...

    Given the point (2, -8) is a turning point of the curve y = f(x), f''(x) = 12x + 18.
  10. U

    Prove 2 Trig Identities

    Prove LHS equals the RHS: 1. (sec²Ѳ - 1)cos²Ѳ = sin²Ѳ 2. 1 / cot²Ѳ + 1 = 1 / cos²Ѳ
  11. U

    Find x-intercepts for...

    y = x^3-2x^2-4x+8 0 = x^3-2x^2-4x+8 I got x = + / - 2, but I'd really like to see how someone else derives their answer. Thanks.
  12. U

    Find the Maximum value and the Minimum value of y for

    Thanks. I did the third option & it didn't match the set answers... so I thought I did something wrong. After looking at it again, they've got y and x in the wrong order... (x = + / - root 2 <-- incorrect in the text).
  13. U

    Find the Maximum value and the Minimum value of y for

    y = sin(x) - cos(x) x is between 0 and 2pi.
  14. U

    Please help - Equation of the Normal Q.

    Nice, thanks guys.
  15. U

    Please help - Equation of the Normal Q.

    Find the equation of the normal to the curve y = tan(x) at the point (pi /3, √3). Thanks.
  16. U

    Wordy Q. about two perpendicular lines & their gradients - Help Please?

    On a topographic map, contour lines join points of equal altitude. Following a contour means you don't go up or down in elevation. The steepest incline / decline is perpendicular to the countours. Suppose I want to know what direction to climb up a mountain (I am in a mountainous region). I...
Top