Using differentials, find the approximate values of the following:
(33)1/5
Let us assume that ![]()
Also, let x = 32 so that x + Δx = 33
⇒ 32 + Δx = 33
∴ Δx = 1
On differentiating f(x) with respect to x, we get
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We know![]()
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When x = 32, we have![]()

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Recall that if y = f(x) and Δx is a small increment in x, then the corresponding increment in y, Δy = f(x + Δx) – f(x), is approximately given as
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Here,
and Δx = 1
⇒ Δf = (0.0125)(1)
∴ Δf = 0.0125
Now, we have f(33) = f(32) + Δf
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⇒ f(33) = 2 + 0.0125
∴ f(33) = 2.0125
Thus, (33)1/5 ≈ 2.0125