Differentiation Question 408
Question: If $ 3\sin (xy)+4\cos (xy)=5 $ , then $ \frac{dy}{dx}= $
[EAMCET 1994]
Options:
A) $ -\frac{y}{x} $
B) $ \frac{3\sin (xy)+4\cos (xy)}{3\cos (xy)-4\sin (xy)} $
C) $ \frac{3\cos (xy)+4\sin (xy)}{4\cos (xy)-3\sin (xy)} $
D) None of these
Show Answer
Answer:
Correct Answer: A
Solution:
$ \frac{dy}{dx}=-\frac{\partial f/\partial x}{\partial f/\partial y}=-\frac{3y\cos (xy)-4y\sin (xy)}{3x\cos (xy)-4x\sin (xy)}=-\frac{y}{x} $ .
BETA
