2cos^2a*cos^2b+2sin^2asin^2b-1=cos2acos2b how to prove it,pleas...

given x=2cos(t)+t*sin(t) and y=2sin(t)-t*cost(t), with t:[pi, 2pi] find all critical values. b...

1-2sin^2(theta/2)=2cos^2(theta/2)-1

how does 2cos^2 x - 2sin^2 x = 2cos2x

2cos^2a*cos^2b+2sin^2asin^2b-1=cos2acos2b

2cos^2a*cos^2b+2sin^asin^b-1=cos2acos2b how to prove it

2Sin tita+2Cos tita=1.5.find tita

If f(x)= (4cos^4x+2cos^2x+2sin^2x-x^9-1/2cos4x)^(1/9). Find f(f(2))

simplify 2sin(pi/6)2cos(pi/6) to an expression of the form (a sin(theta))

Express 1/2cos&+√3/2sin& in terns of Cos& only

2Sin(t) + 2Cos(t) = 1.5

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