## A Level Maths questions

### Differential Equations

please can u help me with this particular question.

Obtain the solution that satisfies the given conditions of the differential equation,

dy/dx = tanxtany , y = pi/4 at x = pi/4

thanks.

### proof that sqrt 2 is irrational

Please can you explain to me the proof for the irrationality of the square root of 2, thanks.

### Solvin logarithmic eqns....So hard..

Solve the equation:

log 3 ( 2-3x) = log 9 (6x^2-19x+2)

### sketching graphs

Hi, suppose u have a graph y=f(x) , how do u draw the graph of y^2=f(x)

### proof

I have been asked to show that 3 + 2x / x <1 (Then there is an arrow, which i am not to sure what it means) then x(x+3)<0

I am very confused this is how i went abaout it but i am obviously wrong:

3 + 2x < x

3 + 2x - x < 0

3 + x < 0

What did i do wrong?

Thanks

### regression

i am doing my stats coursework it is on correlation and bivariate data. i have compared the sizes of the right foot to the left foot in 52 individuals. ive calculated the correlation coefficiant it was 0.916 and i did a hypotheses test which confirmed that the correlation was high but i gave it in last week and my teacher wrote on it that 'correlation doesnt show right = left only that they are connected. perhaps you need to do a regression line to see if y=x' i have calculated my regression line and put it on my graph but i dont understand what the regression line means and what i can say about it. my data is elliptical and the regression line goes through the middle of it. please could you explain the point of the regression line and what the results of it mean?thank u

### exploring attributes of quadrilterals

draw a quadrilterals with only one pair of parrel lines and one right angle. Name this shape.

### Stats - Poisson Distribution

This question is on the S2 syllabus:

Poisson distribution:

Y ~ Po(30)

Estimate : P(Y>28)

The tables in the formula book only go to lamda = 10 but here lamda = 30

How do i do this question??

### Proving identitys

I have been asked to prove the identity

tanx + cotx = 2 / sin2x

The way i was tought was to look at each side seperatly and i have managed to get the left hand side to be

1 / sinxcosx

i am now stuck on the right hand side.

Did i do the left hand side incorrectly?

Thanks for your help

### statistics

can you give some web sites where i can collect between 180-200 items of bivariate data?