Given that the function f (x) = the third power of 1 / 3 * x + the square of M * x, where m is a real number, (1) the tangent slope of function FX at X-1 is 1 / 3, find the value of M, find the process

Given that the function f (x) = the third power of 1 / 3 * x + the square of M * x, where m is a real number, (1) the tangent slope of function FX at X-1 is 1 / 3, find the value of M, find the process

f'(x)=x^2+3mx
k=f'(1)=1+3m=1/3
3m=-2/3
m=-2/9