1.

If A is an obtause angle, then `(sin^(3)A-cos^(3))/(sinA-cosA)+(sinA)/(sqrt(1+tan^(2)A))-2tanA cotA.` is always equal toA. 1B. `-1`C. 2D. none of these

Answer» Correct Answer - B
We have,
`(sin^(3)A-cos^(3)A)/(sinA-cosA)+(sinA)/(sqrt(1+tan^(2)A))-2tanA cotA.`
`=(sin^(2)A+cos^(2)A+sinAcosA)+(sinA)/(|secA|)-2`
`=1+sinA cosA-sinA cosA-2=-1.`


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