If `alpha+beta=pi/2` and `beta+gamma=alpha` then `tanalpha` equals
A. `2(tan beta + tan gamma)`
B. `tan beta + tangamma`
C. `tanbeta + 2tan gamma`
D. `2tan beta + tan gamma`
A. `2(tan beta + tan gamma)`
B. `tan beta + tangamma`
C. `tanbeta + 2tan gamma`
D. `2tan beta + tan gamma`
Correct Answer – c
Given, `alpha+beta=pi//2`
`implies alpha=(pi//2)-beta`
`implies tan alpha = tan (pi//2-beta)`
`implies tan alpha = cot beta`
`implies tan alpha tan beta = 1`
Again, `beta + gamma = alpha ” [given]”`
`implies gamma = (alpha – beta)`
`implies tan gamma = tan(alpha – beta)`
`implies tan gamma = (tanalpha-tanbeta)/(1+tanalphatanbeta)`
`implies tan gamma = (tan alpha-tanbeta)/(1+1)`
`therefore 2 tan gamma = tan alpha – tan beta`
`implies tan alpha=tanbeta + 2 tan gamma`