Melody

$$\\\displaystyle\lim_{t\rightarrow 0}\: \;\frac{tan12t}{sin4t}\\\\\\
=\displaystyle\lim_{t\rightarrow 0}\: \;\frac{sin12t}{cos12t\;sin4t}\\\\\\
=\displaystyle\lim_{t\rightarrow 0}\: \;\frac{sin4tcos8t+cos4tsin8t}{cos12t\;sin4t}\\\\\\
=\displaystyle\lim_{t\rightarrow 0}\: \;\frac{sin4tcos8t+cos4t*2sin4tcos4t}{cos12t\;sin4t}\\\\\\
=\displaystyle\lim_{t\rightarrow 0}\: \;\frac{cos8t+cos4t*2cos4t}{cos12t}\\\\\\
=\frac{cos0+cos0*2cos0}{cos0}\\\\\\
=\frac{1+1*2*1}{1}\\\\
=3$$

I think that this is a very long winded answer

you must work out the probability of 0 than 1 then.... all the way up to 19

sum of r from 0 to 19 of 

40Cr * 0.85^r * 0.15^(40-r)

I apologise for the presentation.

I am on my phone

Just multiply both sides by 8

that's it : )

YES!!             It is fabulous mathematics fun !!

Thanks anon                  

Is this your question?

If  f(3x)=3

what is the value of   (3+x) f(x)=?

Well  f(whatever)=3

so

(3+x)f(x)=(3+x)*3 = 9+3x

Well at least you did not give yourself another 3 points.  

Yes so you could.

It does not look so much like a primary school question/answer any more does it.  

how come you get 6 points for a question you got wrong!   LOL

The question mentions interations so I suppose this is the correct interpretation 

BUT

where does it say in the question that       $$x_n=f(x_{(n-1)})$$

all I see is that   $$f(x)=x^2-i$$

I can certainly see that  $$x_0=1+i$$

I am completely unfamiliar with this wording (notation).