math question need help


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i was wondering if anyone can help me with this question thanks a lot guyz :D

xSiny + ySinx = 1

i have to derive it using implicit derivation

so this is what i have so far......

-Cosy - Cosx dy/dx = 0

not sure if this is right

my head hurts :sleep:

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^newton's derivation basically you derive both sides of the equation using d/dx but when it comes to a variable besides x (i.e y) you derive it according to that variable and then put a d/dx next to it example

x^2 + y^2 = 1

2x + 2y dy/dx = 0

dx/dy = -2x / 2y

get it? its kinda wierd

;)

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Sin x = Cos (90 - x)

Cos x = Sin (90 - x)

But I don't think that's what he wants.

-----

EDIT. NVMD. Forget I even typed that. Hahaha.

So what math is this again?

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Sin x = Cos (90 - x)

Cos x = Sin (90 - x)

But I don't think that's what he wants.

-----

EDIT. NVMD. Forget I even typed that. Hahaha.

thanks but thats not wat i need

This be calculus. Beautiful as my teacher would say...

more like BS calc

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i took AP calc in high school

this is engineering calc

AND I STILL DONT FRIKKIN GET THIS ONE

i did 25 of these and all of them were easy but this one is driving me nuts :blink: :blink: :blink: :blink: :blink: :blink:

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you need to use the product rule.

xsin(y) + ysin(x) = 1

differentiate by term using the product rule:

x*cos(y)*dy/dx + sin(y) + y*cos(x) + sin(x)*dy/dx = 0

solve for dy/dx.

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I think it's actually:

1*sin(y) + x*cos(y) + dy/dx *(sin(x) + y*cos(x)) = 0

But I'm not sure, summer mode has set in on my brain.

hey thanks a lot i think thats right and i simplified more

thanks a lot guys :D :D :D :D

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xSiny + ySinx = 1

[siny + x(cosy)y'] + [y'(sinx) + y(cosx)] = 0

siny + y'(x(cosy)) + y'(sinx) + y(cosx) = 0

y'[x(cosy) + sinx] + [siny + y(cosx)] = 0

y'[x(cosy) + sinx] = -siny - y(cosx)

y' = {-siny - y(cosx)}/{[x(cosy) + sinx]}

* y' = dy/dx

Edited by session
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you need to use the product rule.

xsin(y) + ysin(x) = 1

differentiate by term using the product rule:

x*cos(y)*dy/dx + sin(y) + y*cos(x) + sin(x)*dy/dx = 0

solve for dy/dx.

Ah yeah, knew I missed a dy/dx somewhere, and for some reason I changed it to dy/dx*(sin(x)+y*cos(x)) :wacko:

*quickly goes to change his answer*

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