examples of implicit differentiation?
Sure. Finding \(\ln(x)\).
Finding the derivative of it.
\[\begin{array}{ccc} y&=&\ln(x)\\ e^y&=&x \\ e^yy'&=&1\\ xy'&=&1\\ y'&=& \frac{1}{x} \end{array} \]
Finding the derivative of \(\arcsin(x)\). \[ \begin{array}{ccc} y&=&\arcsin(x)\\ \sin(y) &=& x\\ \cos(y)y' &=& 1\\ \cos(y) &=&\frac{1}{y'}\\ x^2+\left(\frac{1}{y'}\right)^2 &=& 1\\ \left(\frac{1}{y'}\right)^2 &=& 1-x^2 \\ \left|\frac{1}{y'}\right| &=& \sqrt{1-x^2} \\ \left|y'\right| &=& \frac{1}{\sqrt{1-x^2}} \\ \end{array} \]
Technically everything is implicit differentiation, you're just not paying attention. \[y=x^2\] square root both sides, same as to 1/2 power. \[y^{1/2}=x\] take the derivative of both sides with respect to x. \[\frac{ 1 }{ 2 }y^{-1/2}*\frac{ dy }{ dx }=1\] Solve for dy/dx \[\frac{ dy }{ dx }=2y^{1/2}\] Ok looks weird, but just plug in y=x^2 and you get: \[\frac{ dy }{ dx } = 2(x^2)^{1/2}=2x\] Yeah, see, you were always doing the product and chain rule, you just had always done:\[\frac{ d }{dx}(y^1)=1*y^0*\frac{ dy }{ dx }\] without knowing that you took the 1 in the exponent, dropped it down front, subtracted 1, and then used the chain rule. Similarly, with x:\[\frac{ d }{ dx }(x^1)=1*x^0*\frac{ dx }{ dx }=1\] since obviously for every amount of x you go x, so the change of x with respect to itself is exactly 1... clearly... lol.
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