# Thread: past paper question (encounter problems)

1. ## past paper question (encounter problems)

Given that delta (Δ) is an acute angle such that cos delta(Δ)= 1/4x
find the expression for sin 2delta(Δ) in terms of x

how to do such a question??????

2. ## Re: past paper question (encounter problems)

Originally Posted by mathkid12
Given that delta (Δ) is an acute angle such that cos delta(Δ)= 1/4x
find the expression for sin 2delta(Δ) in terms of x

how to do such a question??????
$\displaystyle \cos(\Delta) = \frac{1}{4x}$ or $\displaystyle \frac{1}{4} x$ ???

3. ## Re: past paper question (encounter problems)

second one, 1/4 x (sorry i cant type the equations properly i dont know how??)

4. ## Re: past paper question (encounter problems)

Originally Posted by mathkid12
second one, 1/4 x (sorry i cant type the equations properly i dont know how??)
Then $\displaystyle \sin(\Delta)=\sqrt{1-\frac{x^2}{16}}$

Learn some basic LaTeX.
[TEX]\cos(\Delta)=\frac{x}{4}[/TEX] gives $\displaystyle \cos(\Delta)=\frac{x}{4}$.

thanks alot