Recent content by blackops23

another one:-@ (1) find the probability that in a family of four children 2 are boys and 2 are girls i got 3/8 (2) 2 women each have four children. what is the probability that neither woman has two boys and two girls 25/64?

thanks

-1<=x<=1 observe that: 1=1 2x=x+x 3x^2=x^2 + x^2 + x^2 4x^3=x^3 + x^3 + x^3 + x^3 by studying the above arrangements or otherwise find in simplest algebraic form an expression for the limiting sum of the series: 1 + 2x + 3x^2 + 4x^3 + ... + nx^[n -1]

samantha has 3 similar keys in her pocket. to open her front door she tried the keys at random. she stopped trying when she opened the door and she did not use the same key twice find the probability that (1) the door opened when she tried the first key 2 she tried all three keys before the...

my bad....i swear when i type this on BOS I used ~ instead of =, yeah its approximations....

yeah thats what i did - my answer wasn't close enough

Show that (i) cos 46 (degrees) ~ [(root 2)/360)(180 - pi)] (ii) sin 29 (degrees) ~ (1/360)(180(root 3) - 1)) obv it has something to do with 45 + 1 = 46, and 30 - 1 = 29... i then tried using like...limx--> 0 cosx - 1/x = 1 and lim x-->0 sinx/x = 1....because u no - 1 degree is very close to...

For part (ii) I got A= {[4(a^2)(c^2) - (b^2)(a+c)^2]/2} - is it correct? EDIT: is there an easier way to get the answer?? I did...Area of AOC = (b/2)(sin(theta))(a+c) cos(theta) = [b(a+c)/2ac]....then I drew a right angled triangle....hyptonuse = 2ac, adjacent = b(a+c), and opposite was...

= D = D I got it! once you know the method it was suprisingly easy....but if someone didn't tell me to use areas I would never have been able to figure it out...

(i) show that cos(theta) = [b(a+c)]/2ac (ii) if a=b and c=2b find the area of Triangle AOC No idea how to do part (i)...cosine rule?

no...just no... LOL, have u ever worked in your life shadowdude?

SC results: English - 88 Science - 98 Maths - 97 Geography - 94 History - 93 Computer crap - 95 HSC results: English Standard - 85 biology - 92 Chemistry - 87 3U maths - 95 4U maths - 92

92 in 4U

alcohol is bad for you kidz

Sorry guys someone please explain this to me, how do you know the series is geometric? havent done much work with series :S