Math, asked by jubinjoy432ou61r2, 1 year ago

If sec theta - tan theta=4 ,then find the value of cosec theta

Answers

Answered by kvnmurty
71
Given  SecФ - Tan Ф = 4       ----(1)
Multiply both sides by  SecФ + TanФ to get:

     Sec²Ф - Tan²Ф = 4 (SecФ + TanФ)
=> SecФ + TanФ = 1/4     ---- (2)

From (1) & (2),   SecФ = 17/8   and  Tan Ф = -15/8
So   SinФ = - 15/17

=>  CosecФ = - 17/15            negative real number.

kvnmurty: :-)
jubinjoy432ou61r2: How did u get sin theta from sec theta and tan theta?
kvnmurty: Sine = tan/ sec = tan × cos
jubinjoy432ou61r2: Ok.Now I got it.Thnx bro
ABHAYSTAR: Hey, he is sir not bro so please call him sir ( he is senior of brainly "Kvnmurty sir" )
jubinjoy432ou61r2: Oh sorry. I didn't knew it.
jubinjoy432ou61r2: Thnx sir.I meant no,offence.
Answered by ayushgupta113
44
Sec theta -tan theta=4......1 equation
Multiply both side by (sec theta+tan theta)
We get,sec²theta-tan²theta=4 (sec theta +tan theta)
We get,1=4(sec theta+tan theta)
(Sec theta+tan theta)=1/4.......(2)
equation
From equation (1)and (2) we add
We get,
Sec theta -tan theta=4
Sec theta+tan theta)=1/4
We get, sec theta= 4+1/4
Sec theta=17/8 ,cos theta=8/17
And tan theta=1/4-17/8= -15/8
Then tan theta=sin theta /cos theta
Sin theta=tan theta×cos theta
Sin theta= -15/8 × 8/17 here 8 is cancelled
Sin theta = -15/17 =>cosec theta= -17/15
Similar questions