Question

Obtain the derivative of x^4+cos x. answer is 4x^3-sin x. explain how......best ams will be marked as brainliest...pls no spamming​

Answer 1

Answer :

Let, y = x⁴ + cosx .....(i)

We use the differentiation formulae

d/dx (xⁿ) = n xⁿ⁻¹

d/dx (cosmx) = - m sinmx

Now, differentiating both sides of (i) with respect to x, we get

dy/dx = d/dx (x⁴ + cosx)

= d/dx (x⁴) + d/dx (cosx)

= 4 x⁴⁻¹ - sinx

= 4 x³ - sinx

Therefore, the required derivative is

4x³ - sinx. (proved)