Question

please solve whether y is a function of x
25(x-10)² y² = 81x² .please help!!!!

Answer 1

y = +/- (9x / 5(x-10))
i think it is not ..
consider y^2 = x
y = +/- sqrt(x)
so when x = 5 for example
you get two different y .. which is not a function

the same goes here..

Answer 2

x(y)
you must put it in the form x=...
(25x^2-500x-2500)y^2=81x^2
you will not be able to pull x all alone

Answer 3

\[ 25(x-10)² y² = 81x² \Rightarrow y = \sqrt{\frac{(9x)^2}{(5(x-10))^2}} \Rightarrow y = \frac{(9x)}{5(x-10)}\]

I think this implies \[ y= f(x)= \frac{(9x)}{5(x-10)} \] so y seems to be a function of x

Answer 4

@tutordiffeq: y is a function of x implies \[ y=f(x) \]

Check here: http://www.missouriwestern.edu/cas/Math/Functions.pdf

Answer 5

FoolForMath@ you forgot that it might be +/-..
so it is not a function of x!

Answer 6

@Coolsector: I think ...

\[ \large \sqrt{x^2} = (x^2)^{\frac{1}{2}} = x\]

Hence,...