MathematicsHard63×since 2002Q3665If y = [x+x2−1]15+[x−x2−1]15,{\left[ {x + \sqrt {{x^2} - 1} } \right]^{15}} + {\left[ {x - \sqrt {{x^2} - 1} } \right]^{15}},[x+x2−1]15+[x−x2−1]15, then (x² −-− 1) d2ydx2+xdydx{{{d^2}y} \over {d{x^2}}} + x{{dy} \over {dx}}dx2d2y+xdxdy is equal to :A125 yB124 y²C225 y²D225 yCheck answerSkip