Tính đạo hàm của hàm số 1. y = x^6. (x-2) 2. y = (sin x + cos x) / x 3. y = [căn(2x-1)] / x 4. y = sin^2.(2x – pi/4) 06/08/2021 Bởi Maya Tính đạo hàm của hàm số 1. y = x^6. (x-2) 2. y = (sin x + cos x) / x 3. y = [căn(2x-1)] / x 4. y = sin^2.(2x – pi/4)
1. $y’=(x^6)'(x-2)+x^6(x-2)’$ $=6x^5(x-2)+x^6$ $=7x^6-12x^5$ 2. $y’=\dfrac{(\sin x+\cos x)’x-x'(\sin x+\cos x)}{x^2}$ $=\dfrac{(\cos x-\sin x)x-(\sin x+\cos x)}{x^2}$ $=\dfrac{x\cos x-x\sin x-\sin x-\cos x}{x^2}$ 3. $y’=\dfrac{(\sqrt{2x-1})’x-\sqrt{2x-1}}{x^2}$ $=\dfrac{\dfrac{1}{\sqrt{2x-1}}.x-\sqrt{2x-1}}{x^2}$ $=\dfrac{x-(2x-1)}{x^2(\sqrt{2x-1})}$ $=\dfrac{-x+1}{x^2\sqrt{2x-1}}$ 4. $y’=2\sin\Big(2x-\dfrac{\pi}{4}\Big).\Big(\sin\Big(2x-\dfrac{\pi}{4}\Big)\Big)’$ $=2\sin\Big(2x-\dfrac{\pi}{4}\Big).2\cos\Big(2x-\dfrac{\pi}{4}\Big)$ $=2\sin\Big(4x-\dfrac{\pi}{2}\Big)$ $=-2\cos4x$ Bình luận
1.
$y’=(x^6)'(x-2)+x^6(x-2)’$
$=6x^5(x-2)+x^6$
$=7x^6-12x^5$
2.
$y’=\dfrac{(\sin x+\cos x)’x-x'(\sin x+\cos x)}{x^2}$
$=\dfrac{(\cos x-\sin x)x-(\sin x+\cos x)}{x^2}$
$=\dfrac{x\cos x-x\sin x-\sin x-\cos x}{x^2}$
3.
$y’=\dfrac{(\sqrt{2x-1})’x-\sqrt{2x-1}}{x^2}$
$=\dfrac{\dfrac{1}{\sqrt{2x-1}}.x-\sqrt{2x-1}}{x^2}$
$=\dfrac{x-(2x-1)}{x^2(\sqrt{2x-1})}$
$=\dfrac{-x+1}{x^2\sqrt{2x-1}}$
4.
$y’=2\sin\Big(2x-\dfrac{\pi}{4}\Big).\Big(\sin\Big(2x-\dfrac{\pi}{4}\Big)\Big)’$
$=2\sin\Big(2x-\dfrac{\pi}{4}\Big).2\cos\Big(2x-\dfrac{\pi}{4}\Big)$
$=2\sin\Big(4x-\dfrac{\pi}{2}\Big)$
$=-2\cos4x$
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