Q.

Let α and β respectively be the maximum and the minimum values of the function 

f(θ)=4(sin4(7π2-θ)+sin4(11π+θ))-2(sin6(3π2-θ)+sin6(9π-θ)), θR.

Then α+2β is equal to:                                                               [2026]

1 5  
2 3  
3 4  
4 6  

Ans.

(1)

f(θ)=4(sin4(7π2-θ)+sin4(11π+θ))-2(sin6(3π2-θ)+sin6(9π-θ))

f(θ)=4(cos4θ+sin4θ)-2(cos6θ+sin6θ)

f(θ)=4(1-2sin2θcos2θ)-2(1-3sin2θcos2θ)

f(θ)=2-2sin2θcos2θ

f(θ)=2-sin2(2θ)2

α=f(θ)max=2

β=f(θ)min=32

α+2β=5

Ans.=5 option (1)