MathematicsEasy110×since 2002Q3862Let f_k(x) = 1k(sinkx+coskx){1 \over k}\left( {{{\sin }^k}x + {{\cos }^k}x} \right)k1(sinkx+coskx) for k = 1, 2, 3, ... Then for all x ∈\in∈ R, the value of f₄(x) −-− f₆(x) is equal toA14{1 \over 4}41B512{5 \over {12}}125C−112{{ - 1} \over {12}}12−1D112{1 \over {12}}121Check answerSkip