if sin A + cosec A= 2, find sin^4(A)+cos^4(A)?

• 1 ans.
  sol:-
  sin A+ 1/sin A = 2
  sin^2(A)+1=2sin(A)
  (sin A - 1)^2=0
  sin(A) = sin(90) [since,1=sin 90]
  A=90
  therefore,[sin(A)]^4 + [cos(A)]^4=1^4+0^4=1 ans.[by A=90].
• 12 years agoHelpfull: Yes(4) No(0)
• ans 1
  explaination
  Sin A + cosec A = 2
  sin90 = 1
  cosec90 = 1
  sin90 + cosec90=2
  now sin^4(90) + cos^4(90)
  sin360 + cos360 = 0+1 = 1
• 12 years agoHelpfull: Yes(1) No(1)