value of tan−1sin2−1cos2 is
π2−1
1−π4
2−π2
π4−1
sin2−1cos2=−1−sin2cos2=−(cos1−sin1)2(cos1+sin1)(cos1−sin1)=−cos1−sin1cos1+sin1=−1−tan11+tan1=−tanπ4−1=tan1−π4⇒tan−1sin2−1cos2=tan−1tan1−π4=1−π4