Using tables evaluate the following:`cos^2 0+cos^2 (pi/6)+cos^2 (pi/3)+cos^2 (pi/2)`

cos^2(pi/12)+cos^2(pi/4)+cos^2((5pi)/12)=

Solve the following:find the values of sin^2(pi/2)-cos^2(pi/2)+tan^2(pi/2)

cos(pi/7)cos((2pi)/7)cos((4pi)/7)=

Select and write the correct answer from the given alternatives in each of the following: cos (pi/7) .cos ((2pi)/7).cos((4pi)/7)=

Prove the following: cos(pi/4+x)+cos(pi/4-x)=sqrt2cosx

cos.(2pi)/(7)+cos.(4pi)/(7)+cos.(6pi)/(7)

cos(pi/5)cos((2pi)/5)cos((4pi)/5)cos((8pi)/5)=

Prove the following: cos(3pi/2+x)cos(2pi+x)[cot(3pi/2-x)+cot(2pi+x)]=1

Show that cos^2(pi/4-x)+cos^2(pi/4+x)=1