सही जोड़ी बनाइये -

`{:(,"खण्ड 'अ'",,,"खण्ड 'ब'"),(1.,sin ^( -1)x + cos ^(-1)x,,(a),cot^(-1) (( xy - 1 )/(x + y ))),(2., sin ^(-1) x + sin ^( -1) y,, (b), (pi ) /(2)), (3., tan^( -1) x + tan ^( -1) y ,, (c), cot ^( -1) ((xy + 1 )/(x -y ))), ( 4., cot ^( -1) x + cot ^( -1) y,,(d), cos^( -1)[xy -sqrt( 1 -x ^ 2 )sqrt( 1-y ^ 2 )]),(5., cot^(-1) x -cot ^(-1)y,, (e), sin^(-1) [x sqrt( 1 -y ^ 2 ) + ysqrt(1-x^2)]),(6., cos^(-1)x + cos ^(-1)y,, (f), tan^(-1) ((x +y)/(1-xy))):}`

Answer

1. (b), 2. (e ), 3. (f), 4. (a), 5. (c ), 6. (d)