1) If α=∫10e(9x+3tan−1x)(12+9x21+x2)dx, where tan-1 x takes only principal values, then the value of loge|1+α|−3π4 is A) 8 B) 7 C) 9 D) 4 Answer: Option CExplanation:Here , α=∫10e(9x+3tan−1x)(12+9x21+x2)dx Put 9x+3tan−1x=1 ⇒ (9+31+x2)dx=dt ∴ α=∫9+3π/40etdt=[et]9+3π/40 = e9+3π/4−1 ⇒ loge|1+α|=9+3π4 ⇒ loge|α+1|−3π4=9