If cos2θ -sin2θ=1/3, value of (cos4θ-sin4θ+1) is:
(A) 4/3

(B) 5/3

• Hello Arjun..
  Can you please post the problem more clearly once again..The problem u have posted can't be clearly made out..
• 12 years agoHelpfull: Yes(3) No(0)
• trigonometry question
  
  (my question is cos square theta minus sin square theta equal to one-third so find the value of cos four theta minus sin four theta plus one)
  Question:
  If cos2θ -sin2θ=1/3, value of (cos4θ-sin4θ+1) is:
  
  (A) 4/3
  
  (B) 5/3
• 12 years agoHelpfull: Yes(0) No(0)
• i think it is cos^4 instead of cos4
• 12 years agoHelpfull: Yes(0) No(1)
• cos^4theta-sin^4theta=(cos^2theta-sin^2theta)(sin^2theta+cos^4theta)=1/3*1=1/3
  now 1/3+1=4/3
• 12 years agoHelpfull: Yes(0) No(0)