MathematicsHard63×since 2002Q3674Let f(x)=sinx+cosx−2sinx−cosx,x∈[0,π]−{π4}f(x)=\frac{\sin x+\cos x-\sqrt{2}}{\sin x-\cos x}, x \in[0, \pi]-\left\{\frac{\pi}{4}\right\}f(x)=sinx−cosxsinx+cosx−2,x∈[0,π]−{4π}. Then f(7π12)f′′(7π12)f\left(\frac{7 \pi}{12}\right) f^{\prime \prime}\left(\frac{7 \pi}{12}\right)f(127π)f′′(127π) is equal toA233\frac{2}{3 \sqrt{3}}332B29\frac{2}{9}92C−133\frac{-1}{3 \sqrt{3}}33−1D−23\frac{-2}{3}3−2Check answerSkip