given f(x)=x^4 (iv) stuck
i) complete this identity f(x+h) = x^4+4x^3h+...
iii)find lim h tends 0 of ii)
iv)state what this limit represents
the answer is gradient of (tangent to) curve but i'm not sure why. If someone could explain to me the reasoning then i could apply it to other q's,thnx