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I need to find the absolute value of b(t): b(t)=a(t)[1+e^{-j2\pi tT}] Here is the answer in the textbook: \therefore \left | b(t) \right |=\left | a(t) \right |\sqrt{2(1+cos(2\pi tT)}2|cos(\pi tT)| However I got a different answer when working it out, and can't understand how they got to that...

ABCD is a parallelogram. The coordinates of A,B and C are (-1,4), (4,6) and (2,7) respectively. Find the coordinates of D. I got D(1,3) but the answer says: D(-3,5) Working out: mAD = (7-6)/(2-4) = -1/2 AD: y = (-1/2)x + 7/2 mBD = (7-4)/(2+1) = 1 BD: y = x + 2 Find the intersection which...

A circle touches the +ve x and y axes and also passes through the point (1,2). Determine the centre and radius of all such circles. The question says 'of all such circles' but shouldn't there just be only 1 circle with this description? I tried to work it out but I didn't know to get exact...

Hi, f(x) = (x^2 - x + 1)/(x - 1) I tried to sketch this, I worked out the limit as x --> infinity, and found that it is f(x) = x - 1, but when you sub in x = 0, you get f(0) = -1, but according to the asymptote this shouldn't be allowed right? When I sketched the graph I saw that f(x) passes...

A triangle has 1 side of length x, another side of also length x, and a 3rd side of length 2. Find x.

How would you work this out?: This is the answer to the integral, just need to sub in values for t. (1/4)[(e^(j4PIct - j2PIft))/(j4PIc - j2PIf)] from t = infinity to t = -infinity. Hope you guys can help.

Find the limit as x--> infinity (3x^2)/(x-1) I worked it out to be infinity, but the answer is 3x, which you get when you divide everything by the highest power of the denominator. And 1/x is considered 0 so you get 3x/1 = 3x. But how is the answer 3x? As x approaches infinity, you have 3 x...

Find the limit as x --> 2 (|x^2 + x -6|)/(x-2) If you sub in 2 you get 0, but if you factorise: (|(x-2)(x+3)|)/(x-2) are you allowed to cancel the (x-2) and just have x+3 and then sub in 2 and it gives 5? I wasn't sure if you can cancel the x-2 because the numerator is absolute value?

Sally decides to put $100 per week into her superannuation fund. The interest rate quoted is 8% per annum, compounded weekly. Which expression will calculate the future value of her superannuation at the end of 35 years?

How would you factorise this?: s^3 + 5s^2 + 8s + 4

Huong used the 'capture-recapture' technique to estimate the number of trout living in a dam. She caught, tagged and released 20 trout. Later she caught 36 trout at random from the same dam. She found that 8 of these 36 trout had been tagged. What estimate should Huong give for the total...

Find the sum of 10 terms of the series log3 + log6 + log12 +........ gvien that log3 = 0.4771 and log2 = 0.301. (All logs are base 10). I couldn't work this out because it doesn't seem to be an AP or a GP, because log6/log3 doesn't equal log12/log6.

Hi, I had a bit of trouble with this question: The point (2,1) lies on the circle with equation x^2 + y^2 + 6x - 2y -15 = 0 Find the coordinates of the other end of the diameter through (2,1) I worked out the centre of the circle to be (-3,1) and radius = 5. So I tried to use the distance...

Find the locus of a point P which moves so that: PA^2 - PB^2 = 5 I don't know how to work this out without first knowing the location of A and B. Hope you guys can help!

Hi How do you solve this equations analyticaly without solving a 4th degree polynomial sqrt(x)+y=11; x+sqrt(y)=7 Thanks for the help!

If x is between 180 and 270 degrees and sinx=p, express cosx in terms of p. I know the answer is this but have no idea how to get there, hope you guys can help: cosx= -sqrt(1 - p^2)

Hi, just need a bit of help with this question: P(A or B) = 15/16, P(A and B) = 2/16, P(A) = 6/16, P(B) = ? I know the answer is P(B) = 11/16, but I've got no idea how to get that answer. I know or means + and 'and' means * but I still got the wrong answer.

Hi, I just got a job as a maths tutor for a 3unit yr 11 kid. When you start yr 11 3unit, do you start off with the 2unit stuff that other yr11/12 2unit students do aswell? And then when you start yr 12 you start doing the 3unit stuff? Also I have these 2 books, do you guys still use them...

Hi. y'' + 2vy' + w^2y = 0 r = +/- iw ---------------------------------------------------------------------- if r = p +/- iq then p = 0 and q = w ---------------------------------------------------------------------- y(t) = (Ae^pt)cosqt + (Be^pt)sinqt therefore y(t) = Acoswt + Bsinwt...

Hi, I'm about to start telecommunications engineering, but I'm starting to think maybe electrical engineering would be more interesting, is it possible to change? does anyone know which industry will need more employment in the future?