" If "cos theta=(1)/(2)(a+(1)/(a))," then "cos3 theta" is "

If cos theta=(1)/(2)(a+(1)/(a)) then show that cos3 theta=(1)/(2)(a^(3)+(1)/(a^(3)))

If cos theta=(1)/(2)(a+(1)/(a)) and cos3 theta=(1)/(2)(a^(k)+(1)/(a^(k))) then number of natural numbers 'k' less than 50 is

If cos theta = 1/2 (a+(1)/(a)), then the value of cos 3 theta is

If cos theta=(1)/(2)(a+(1)/(a)),cos3 theta=lambda(a^(3)+(1)/(a^(3))), then lambda(a)-(1)/(4) (b) (1)/(4) (c) 1 (d) none of these

If cos theta = 1/2 (a+(1)/(a)), then the value of cos 3 theta is ............. A) 1/8 (a ^(3) +(1)/(a ^(3))) B) 3/2 (a+(1)/(a)) C) 1/2 (a^(3) + (1)/(a^(3))) D) 1/3 (a^(3) +(1)/(a ^(3)))

cos theta=(1)/(2)(a+(1)/(a)) and cos3 theta=k(a^(3)+(1)/(a^(3))) then K=

i) Prove that: (1-sin2A)/(1+sin2A) = tan^(2)(pi/4-A) ii) If costheta=1/2(x+1/x) , then prove that: cos2theta=1/2(x^(2)+1/x^(2)) and cos3theta=1/2(x^(3)+1/x^(3))

i) Prove that: (1-sin2A)/(1+sin2A) = tan^(2)(pi/4-A) ii) If costheta=1/2(x+1/x) , then prove that: cos2theta=1/2(x^(2)+1/x^(2)) and cos3theta=1/2(x^(3)+1/x^(3))

If theta = pi/(2^(n) + 1), "show that",2^(n) cos theta cos 2 theta cos2^(2) theta cos2^(3) theta.... cos2^(n-1) theta = 1.

If sintheta_(1)+sintheta_(2)+sintheta_(3)=3, then cos theta_(1)+cos theta_(2)+cos theta_(3)=