Verified answer

(xⁿ)' = n•x^n-1

а)f'(x) = x⁴-3x²

б)f'(x) = (x)'•sinx + (sinx)'•x = sinx+xcosx

в)f'(x) = 6(2x-6)^5 • 2 = 12(2x-6)^5

f'(1) = -12•4^5 = -3•4^6