Question 76

Find$$ (1 - cos^{2}\theta )(cot^{2}\theta + 1) - 1$$.

Solution

sin^2(θ)+cos^2(θ)=1 

1+cot^2(θ)=cosec^2(θ)

(sin^2(θ)+cos^2(θ)=1)

(sin^2(θ)=1cos^2(θ))

Now let's substitute:

((1cos^2(θ))(1+cot^2(θ))-1

((sin^2(θ))(cosec^2(θ)))-1

The relationship between sin and cosec is:

cosec=1sin

thus

cosec^2(θ)=1sin^2(θ)

and so ((sin^2(θ))(1sin^2(θ)))-1=1-1 = 0 


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