step by step solution please

Let ( a 1, ..., an) E RF and x = (X1, ...,Xn) E RT+. Let A > 0,u > 0,p # 0. (10) Define the generalised CES function f over the convex set R? "+Hy = XA f(x) = A(dix, + a2x2 + "..antn) Using the results from this question, show that this generalised CES function f is a quasiconcave function over RT. when p E (0, 1]