If cot α = 1 and sec β = - 5 3 , where π < α < 3 π 2 and π 2 <…

If cotα=1 and secβ=-53, where π<α<3π2 and π2<β<π, then the value of tanα+β and the quadrant in which α+β lies, respectively are
  1. -17 and IVth quadrant
  2. 7 and Ist quadrant
  3. -7 and IVth quadrant
  4. 17 and Ist quadrant

Solution

Given,

cotα=1,secβ=-53

So, cosβ=-35,tanβ=-43 and tanα=1

Now using formula tanα+β=tanα+tanβ1-tanαtanβ

tanα+β=1-431+43×1=-17 

We know that tanθ is negative in 2nd & 4th  quadrant but as π<α<3π2, so α+β will lie in IVth quadrant.

Asked in: JEE Main 2022 (28 Jun Shift 2)

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