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Sinx2627Find the derivative of (x2-3x+2)(x+2)wrt x.Find the mean deviation about of first fi​

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Question:-

Find the DERIVATIVE of (x² - 3x + 2)(x + 2) wrt x.

Answer:-

METHOD - 1:-

\implies \sf \:  \dfrac{d}{dx} (x ^2  - 3x + 2)(x + 2)

USING;

d/dx (uv) = v × du/dx + u × dv/dx we get;

\implies \sf \: (x + 2) \times  \frac{d}{dx} ( {x}^{2}  - 3x + 2) + (x ^{2}  - 3x + 2) \times  \frac{d}{dx} (x + 2) \\  \\  \\ \implies \sf \:(x + 2) \times  (2 \times  {x}^{2 - 1}  - 3 \times  {x}^{1 - 1}  + 0) + ( {x}^{2}  - 3x + 2)(1 \times  {x}^{1 - 1}  + 0) \\  \\  ( \because \sf  \frac{d}{dx} (constant) = 0 \:  \:  \& \:  \:  \frac{d}{dx} ( {x})^{n}  = n \times  {x}^{n - 1}  \: ) \\  \\  \\ \implies \sf \: (x + 2)(2x - 3) + ( {x}^{2} - 3x + 2)(1) \\  \\  \\  \implies \sf \: x(2x - 3) + 2(2x - 3) +  {x}^{2}  - 3x + 2 \\  \\  \\ \implies \sf \: 2  {x}^{2}  - 3x + <klux>4X</klux> - 6 +  {x}^{2}  - 3x + 2 \\  \\  \\ \implies  \boxed{\sf \: 3 {x}^{2}  - 2x - 4}

Method - 2:-

(x² - 3x + 2)(x + 2) = x(x² - 3x + 2) + 2(x² - 3x + 2)

= x³ - 3x² + 2x + 2x² - 6x + 4

= x³ - x² - 4x + 4

Now,

DIFFERENTIATING with respect to x we get;

\implies \sf \:  \frac{d}{dx} ( {x}^{3}  -  {x}^{2}  - 4x +4 ) \\  \\  \\ \implies \sf \:3 \times  {x}^{3 - 1}  - 2 \times  {x}^{2 - 1}  - 1 \times 4 \times  \times  {x}^{1 - 1}  + 0 \\  \\  \\  \\ \implies \boxed{ \sf \: 3 {x}^{2}   - 2x - 4}



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