If `cos9alpha=sinalpha` and `9alpha lt 90^(@)`, then the value of `tan – InterviewSolution

InterviewSolution

1.	If `cos9alpha=sinalpha` and `9alpha lt 90^(@)`, then the value of `tan5alpha` isA. `1/sqrt(3)`B. `sqrt(3)`C. 1D. 0
Answer» Correct Answer - C Given, cos`9alpha=sinalpha` and `9alpha lt90^(@)` i.e., acute angle. `sin(90^(@)-9alpha)=sinalpha` `[therefore cosA= sin(90^(@)-A)]` `rArr 90^(@)-9alpha=alpha` `rArr alpha=9^(@)` `therefore tan5alpha=tan(5 xx 9^(@))= tan45^(@)=1` `[therefore tan45^(@)=1]`

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