Differentiate each of the following functions by the product by the product rule and the other method and verify that answer from both the methods is the same.
(3x2 + 2)2
Let, y = (3x2 + 2)2 = (3x2 + 2)(3x2 + 2)
⇒ y = 9x4 + 6x2 + 6x2 + 4
⇒ y = 9x4 + 12x2 + 4
Differentiating y w.r.t x –
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Using algebra of derivatives, we have –
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Use formula of derivative of above function to get the result.
⇒
{∵ ![]()
∴
…equation 1
Derivative using product rule –
We have to find dy/dx
As we can observe that y is a product of two functions say u and v where,
u = (3x2 + 2) and v = (3x2 + 2)
∴ y = uv
As we know that to find the derivative of product of two function we apply product rule of differentiation.
By product rule, we have –
…equation 2
As, u = (3x2 + 2)
∴ ![]()
⇒ ![]()
⇒
…..equation 3 {∵
}
As, v = (3x2 + 2)
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⇒ ![]()
⇒
…equation 4 {∵
}
∴ from equation 2, we can find dy/dx
∴ ![]()
using equation 3 & 4, we get –
⇒ ![]()
⇒ ![]()
Hence,
….equation 5
Clearly from equation 1 and 5 we observed that both equations gave identical results.
Hence, Results are verified