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Prove that 2 sin^2 beta + 4 cos(alpha +...

Prove that `2 sin^2 beta + 4 cos(alpha + beta) sin alpha sin beta + cos 2(alpha + beta) = cos 2alpha`

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ALLEN-BASIC MATHS,LOGARITHIM, TRIGNOMETRIC RATIO AND IDENTITIES AND TRIGNOMETRIC EQUATION -EXERCISE (S-1)
  1. Solve the inequality: log(x)2.log(2x)2. log(2)4x gt 1

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  2. Prove that : cos^2alpha+cos^2(alpha+beta)-2cosalphacosbetacos(alpha+be...

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  3. Prove that 2 sin^2 beta + 4 cos(alpha + beta) sin alpha sin beta + co...

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  4. sin^4(pi/16)+sin^4(3pi/16)+sin^4(5pi/16)+sin^4(7pi/16)=3/2

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  5. If x=sin(theta+(7pi)/(12))+sin(theta+pi/(12))+sin(theta+(3pi)/(12))dot...

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  6. 6. Find the positive integers p, q, r, s satisfying tan (pi/24)=(sqrt(...

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  7. if m*tan(theta-30)=n*tan(theta+120), show that cos2theta=(m+n)/(2(m-n)...

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  8. If cos(alpha+beta)=4/5; sin(alpha-beta)=5/13 and alpha,beta lie betwee...

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  9. If the value of the expression sin 25^@* sin 35^@* sin 85^@ can be exp...

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  11. Prove that 4cos((2pi)/7).cos(pi/7)-1=2cos((2pi)/7).

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  12. Let P(k)=(1+cospi/(4k)) (1+cos((2k-1)pi)/(4k)) (1+cos((2k+1)pi)/(4k))...

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