If a=sin−1(22)+cos−1(−21) and b=tan−1(3)−cot−1(−31), then find the value of a+b.Answer: 127πSolutionNote 22=21, so sin−121=4π and cos−1(−21)=32π.a=4π+32π=1211πAlso tan−13=3π and cot−1(−31)=π−3π=32π (angle in (0,π)).b=3π−32π=−3πa+b=1211π−3π=1211π−4π=127π127πCBSE Class 12 Board · 2024 · Subjective