#Calculus 1 Derivatives

44 messages · Page 1 of 1 (latest)

safe warren
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Good afternoon guys, I was wondering if anyone could explain to me and guide me with steps into solving these derivatives as halfway into solving the problem I would always get stuck.Your help would be very much appreciated

lunar crownBOT
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tawny bramble
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Product
Given $y=f(x)g(x)$, $\frac{dy}{dx}= f’(x)g(x) + f(x)g’(x)$

wheat heathBOT
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r•eⁱˣ = r•cos(x) + ri•sin(x)

tawny bramble
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Chain:
Given y = f(g(x)), $\frac{dy}{dx} = f’(g(x))g’(x)$

wheat heathBOT
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r•eⁱˣ = r•cos(x) + ri•sin(x)

safe warren
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yes I do know the rules

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my issue is the step whereby i have to combine the product rule with the chain rule

stone pewter
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tharts not hard

trail viper
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You can use logarithmic differentiation for the first one it's easier

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Take the natural logs of both sides and then differentiate w.r.t x

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Lemme do the first step for you

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$$y = \frac{2 \cos{x²}}{3x-1}$$

wheat heathBOT
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AstroVortex

trail viper
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So after taking the natural logs

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$$\ln{y} = \ln{\frac{2 \cos{x²}}{3x-1}}$$

wheat heathBOT
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AstroVortex

trail viper
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Using prop6erties of logs:-

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$$\ln{y} = \ln{2\cos{x²}} -\ln{(3x-1)}$$

wheat heathBOT
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AstroVortex

trail viper
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You can further break it up if you want

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$$\ln{y} = \ln{2} + 2\ln{\cos{x}} - \ln{(3x - 1)}$$

wheat heathBOT
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AstroVortex

trail viper
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Now differentiate both sides w.r.t x

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Ping me if you need further help

trail viper
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@safe warren do you need further help?

stone pewter
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@trail viper nah he doesn't

trail viper
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Ig I'll solve them for him

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with steps

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The second one, y = sin(sin 2t) can be solved using the chain rule

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According to chain rule, d/dx f(g(x)) = f'(g(x))•g'(x)

trail viper
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Now use the chain rule

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So d/dx sin(sin 2t) = cos(sin 2t)•cos 2t

safe warren
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Thank you so much guys ,sorry for the late reply

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I have a better understanding now. I will come back to you if I have any more questions

trail viper
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Yeah sure

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Ping me if you need further help

stone pewter
half quiver
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Couldn’t u do some quotient rule

trail viper
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yeah but i think logarithmic differentiation us easy there