Need help on numbers 6, 7, and 8 ill mark brainliest if they are right

please explain how you got the answer

If y varies directly as x2 and y=6 when x=6, find the constant of variation.

Find the value of x. give reasons to justify your solutions! l, m ∈ kn

A) find the derivative of the inverse to f(x) = 3x + sint at x 6. b) (cale) find the derivative of the inverse to f(x)+3sin at x 6. if x +2y -34, ind he behaviar of the cure at 4,.3), c) a. increasing, concave up d. decreasing, concave down b. increasing, concave down e. decreasing, inflection point c. decreasing, concave up