Maths p1 urgent help

[Hasnain1sds]

Could somebody pls explain the following problems:

1- O/N 2005 p1 Q5 i)

2- O/N 2006 p1 Q2

3- O/N 2007 p1 Q4

4- O/N 2008 p1 Q9 iii)

5- O/N 2009 p1 Q10 C)


- Thankyou

 

[Mortal9090]

1:

om/ot=pm/at
12-h/12 = r/6
12-h=12(r/6)
h=12-2r ans

V=pi*r^2*h
copy h from above to prove.

 

[mrpaudel]

2. that means...SInx=3/5.....
a)Cos^2(x)=1-Sin^2(x)= 1-(3/5)^2
b)Tan^2(x)=Sin^2(x) /Cos^2(x) ...substitute likewise..!!

3.
i) 5th term=a+4d 15th term=a+14d
ii) 1st 5th and 15th term are consecutive terms in G.P.....so
15th term/5th term = 5th term/1st term
or, a+14d/a+4d = a+4d/a.
now solve this...u wil get 3a=8d..
iii) Common ratio= 5th term/1st term = a+4d/a......now from (ii) d=3a/8...So
[a+4*(3a/8)]/a gives u a ratio after "a" gets cancelled...

4.
iii) calcalute the equation of both tangents.....both are straight line....so compare both equations with y=mx+c.....Now u wil get two slopes.....Lets say...slope for 1st tangent=m1 and slope for 2nd tangent=m2.........so angle between two lines is given by the formula,
tanA=(m1-m2)/(1+m1*m2)

 

[mrpaudel]

5.do as number 4..!!

any more questions..or any xplaination u didnot get...u can ask instantly....m always ready to help for any1..as much as i can!!