• If CosecA - SinA = a3, SecA - CosA = b3 , then Prove That a2b2 (a2 + b2) = 1
  • If Tn = SinnA + CosnA, P.T ( i ) : T3 - T5 / T1 = T5 - T7 / T3 ; ( ii ) : 2T6 - 3T4 + 1 = 0 ; ( iii ) : 6T10 - 15T8 + 10T6 - 1 = 0

cosecA-sinA=a3

=> 1/sinA-sinA=a3

=>(1-sin2A)/sinA=a3

=>cos2A/sinA=a3 -----  i

Again, secA- CosA= b3

=>1/cosA-CosA=b3

=>(1-cos2A)cosA=b3

=> sin2A/cosA=b3 ------ ii

Now, i x ii =>

cos2A/sinA x sin2A/ cosA = a3b3

=>cosAsinA=a3b3------ iii

i --> cos(square)A/sinA=a(cube)

=>cos2A=sinA.a3

=>cos3A=cosAsinA.a3 [multiplying both sides by 'cosA']

=>cos3A= a3b3.a3  [from iii]

=>cos3A=A6b3

=>CosA=a2b

=>cos2A=a4b2---- iv

 ii --> 

sin2A/cosA=b3

=>sin2A=cosA. b3

=>sin2A.sinA=cosA.sinA.b3 [multiplying both sides by 'sinA']

=>sin3A=cosAsinAb3

=>sin3A=a3b6

=>sinA=ab2

=>sin2A=a2b4 ------ v

Now, iv + v =>

sin2A+cos2A=a2b4+a4b2

=>1=a2b2(a2+b2)

Proved.

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1.

2. Try solving it by Yourself first.

 

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is there any simpler method to solve this problem
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